How to uninstall apps on my Mac that won't delete?

Your focus is getting rid of all the Following types of third party apps installed:

• Antivirus
• Cleaning
• Security
• VPN
• Maintenance

the correct method is to locate the developers uninstall instructions and follow those. Them download FindAnyFile and have it search the system for anything that has those names. For example on Avast, locates the developers uninstall instructions and follow the let FindanyFile search for anything with “Avast” in it , move to the Trash and empty the Trash.

You created a MAJOR problem that if you are fortunate you can get out of. If you cannot you will need to do a full erase and install and start over from scratch!

All these programs have built-in uninstallers, and it's best to use them. If you're concerned about leftover files these programs might leave in system folders and the Library folder, you can search inside these folders by the name of the programs you've uninstalled. You can also use a free utility like Onyx X to clean up caches after removing software.

Also, most likely, you are attempting to delete some Apple apps which are installed as part of the Apple operating system. That cannot be removed. You can only delete apps which are separately installed by you.

What apps are you referring to and what exactly do you mean by "conventional means", you must be specific as we have no idea what apps you are referring to and the conventional means you refer to.

Exactly which apps are you referring to?

BTW, apps built into macOS cannot be removed.