Why is Sonoma so slow to start up?

Disconnect ALL External Drives - Firstly

To avoid the question / answer and question answer scenario

Suggest the User start with Points 1 to 4 and then Test

Still having issues, move onto Steps 5 and 6 and Test Again

Still no resolve - move onto Step 7 and follow instructions therein 

1 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Safe Mode will also eliminate Third Party Software, extensions and drivers from loading. It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance 

3 - Does the issue present in this mode ?

4 - Sometimes a Safe Boot followed by a Normal Boot will just put things right.

5 - If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

6 - If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

7 - Download the Application Etrecheck directly from the Developer.

The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 

This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<

Short answer and not being fipplent.

Would suggest exploring in purchasing a new or newer computer with a Solid State Drive ( SSD ) with a drive capacity of at least equal to or larger than your current 1.00TB Mechanical - 5400 ROM  - Fusion) drive 

While your are at it, make sure the RAM is at least 16 GB 

Both the above will help future-proof your anticipated computer needs

Notation -  New or Newer Apple computers can not UpGrade the Drive nor the RAM after purchase.

Both are Soldered to the Logicboard

Why is the above suggested.

Rotational / Mechanical Drives are slow and will always be slower than SSD Drives 

Mechanical Drives have a Platter spinning with the Read and Write Heads passing over the spinning drive to Read and Write to / from the Drive.

SSD Drives have no moving parts.

Then the Software presently installed on the computer 

DrCleanerProPlus, Avira, and Malwarebytes

None of the above are needed or required 

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

The Operating System resides in a Sealed and Read Only Volume that can not be opened by the User nor by Third Party Applications.

The only Entity that can open and modify or alter this Volume is Apple.

That would occur when an update or UpGrade is performed.

The Only thing this Antivirus software is protecting is the Bank Account of the Developers and for zero return to the User aside from the problems this software creates.

AntiVirus Developers purposefully Market their product to create a “ Fear Factor “. In so doing, creating a False Need for their Product.

Any of the below should be removed as per Developers Instructions 

1 - Disk Cleaner 

Dr Cleaner Pro Plus

2- Third Party Security Software 

 Avira 

The The Built in Security  is all that is required.

Mac app security enhancements

Security. Built right in

You could spend days or weeks attempting to remove all the bit and pieces of these softwares and never get every bit off the drive 

Thank you for the advice. In anticipation of your answer I had already uninstalled Malwerbytes and Dr Cleaner.

What about Avira?

You need to gut all of the garbageware you have installed and test.

It may be worth a complete nuke and pave, test, then install only what you truly need.

I can't remember which OS caused problems with the Fusion Drives, might have been Ventura, and this might be the same issue. If that is the case, cleaning up all the garbage won't solve anything. It was quite a few updates before they finally made it work. A lot of people bought external SSDs and booted from those.

Did you not suffer similarly with Ventura or did you not upgrade until later after they fixed it.

Welcome

Should to decide and not suggesting it will Solve the Speed issue.

It will make a clean installation and thereby remove the AV Software etc. already mention earlier

This method will WIPE ALL Data and there is No DATA Recovery - Period.

>> Only works on Intel Based Apple Computer <<

To perform this action will require booting from a Bootable Installer. 

The Bootable Installer can Only be performed on an Apple Computer 

This will have to be performed from a Qualifying Computer to run the version of macOS to be made on the Bootable Installer.

Example : Bootable Installer of Sonoma would have to be done on a computer that Qualifies to run Sonoma.

1 - Shutdown computer and disconnect all external drive Except the newly created Bootable Installer.

2- Restart and immediately hold the OPTION key until the Startup Manager appears and choose the USB Drive. 

3 - It will present options >> Disk Utilities >> View >> View ALL attached Drives. 

4 - Choose the Upper Most Drive ( not the volumes indented and list below ).

5 - The drive normally is called Apple Media or Apple SSD - that is the drive to Erase and format as APFS with the GUID Partition Map.  

6 - Once that is done >> backup out of Disk Utilities and choose install macOS. 

7 - Follow the prompts and it may automatically reboot several time. 

8 - Upon a final reboot - Setup Assist will present with the newer version of macOS.

9 - Would suggest Only Migrating the User Account and nothing more.

10 - Best to only install new applications etc Directly from the Developer or the Apple Apps Store

11 - Leaving out the AV and Disk Cleaner Applications for reasons already mentioned

FWIW, you still need to uninstall Avira. You didn't actually have to uninstall Malwarebytes, disabling real time protection would suffice.

The Above will Copy the Etrecheck Report to the Clipboard

Example below and only an illustration of what is on the clipboard

Then using the illustration in below image

Paste the Report and post as reply

From the report…

System Extensions:

[Running] Avira Scan Service - version 8.1.0 (Avira Operations GmbH & Co. KG - 2022-02-26)

TEXT is what in needed not data

Yes Sonoma 14.1 is out

Though, with such a slow booting computer as this one with 14.0 it may or maybe Not fix the issue

In fact it may or may not make the machine work just the same as now

Thank you and I see the report

Will get back to you shortly

A Very quick scan of the text indicates this is a Mechanical / Rotational / Spinner Drive and has several AntiVirus Software softwares installed

Neither of the two are boding well for this computer experience

EDITED

Follow on

Explore the Apple Trade-In  Process where the Value of the exiting device could be used against the cost of a new Apple Computer

Notation - Some devices and depending on the computers age may have little to no value at Trade In time.

But at least the device will not arrive to the Land Fill Site and be recycled in a responsible way by Apple

Or Shop Refurbished Apple computers at an Apple Reduced Cost

Have used both previously and have been satisfied each time.