Old SSD unbootable/unrecognizable

Well it appears the partition or actually the hidden Container is not even recognized on the SSD, but is listed as "free space". I'm really concerned that this could mean the data is already gone due to how SSDs work. If this were a hard drive, then the data could very well still be there, but with an SSD it is hard to say.

The safest option is to contact a professional data recovery service such as Drive Savers. They provide free estimates and are recommended by Apple and other OEMs. You can try using data recovery software as already suggested, but sometimes these apps may make modifications to the source drive which is really bad if you ever want to use a professional data recovery service later on (you have the original issue, plus unknown modifications by the app).

Actually when using a data recovery app, the safest approach would be to perform a low level block for block (bit for bit) clone of the SSD so you can attempt data recovery from the clone instead so it keeps the original drive intact if you wanted to use a professional data recovery service. However, the only way I know to perform such a low level clone is using a command line utility which is dangerous since it is very easy to make a mistake in marking the source & destination drives.

Another option using a command line utility is to attempt to restore the partition table from the backup copy which is stored on the SSD. I have done this only once or twice on a Mac many years ago. Again, this is risky because it is making a change to the SSD especially if you want to have a professional data recovery service work on it for you. With an SSD there is a bit more risk because it is hard to say what will happen as it could possibly trigger the data to be erased due to how SSDs work (if this hasn't already happened). With a hard drive the risk would be minimal as the data would still be stored on the drive, although it could affect a data recovery service when examining the drive, but I honestly cannot say when it comes to an SSD since I have never had to deal with this situation.

The hard drive SATA cable inside this laptop may be bad since the cable has an extremely high rate of failure especially when used with an SSD. Has anyone tried removing the SSD and connecting it to a Mac using a USB to SATA Adapter, drive dock, or enclosure?

I would also suggest trying to access the SSD's health report. This can be done from macOS by using the DriveDx app. Or it can be done if the SSD is connected to a Windows or Linux system by using GSmartControl. If you can retrieve the health report, then post it here so it can be examined.

Yes, those UDMA CRC Errors most likely indicate a bad cable.

As for accessing the data on the drive you use this drive to boot a later Mac, especially an M1 Mac, however, you should be able to access the data on the SSD. The tricky part is that M1 Macs have compatibility issues with some USB chipsets found in USB Adapters, drive docks and enclosures, and macOS 12.x Monterey sometimes has its own compatibility issues as well.

If you had Filevault enabled on the older Mac, then you may need to use Disk Utility to manually mount the external drive since sometimes macOS won't automatically provide a pop-up window prompting to unlock the encrypted external drive.

Another problem I have encountered with Filevaulted APFS volumes is that sometimes the volume will be unlocked, but won't mount due to an APFS file system error. Unfortunately macOS doesn't tell the user any of this and just silently fails. After using Disk Utility to Mount the SSD, try running First Aid on the physical drive (and the hidden Container if it is visible). Within Disk Utility you may first need to click "View" and select "Show All Devices" before the physical drive and physical Container appear on the left pane of Disk Utility. Even if First Aid says everything is "Ok", click "Show Details" and scroll back through the report to see if any unfixed errors are listed (yes the summary screen will lie to you).

If none of this works, then you can try using the command line to manually mount the APFS volume on the SSD in read-only mode if the drive us unlocked. You will want to mount the "Data" volume (or "Macintosh HD - Data" volume). It can be a little tricky & difficult to guide you on this part as it will involve some back & forth questions & answers, but showing the output of these two commands from the Terminal app will help. Make sure to attempt to manually mount the external drive using Disk Utility first since it will affect the output of these two commands and that information is very important to us. I'm assuming the SSD is connected externally, but if the SSD is installed internally, then change "external" to "internal" in the following command:

diskutil  list  external

diskutil  ap  list

If the drive is getting unlocked, but won't mount (I've seen this several times with our organizations Macs), then we can try to help you mount it as read-only, otherwise you can attempt to use data recovery suggested by @BDAqua.

It's highly unlikely to recover data from SSDs, but...

Data Rescue II...

http://www.prosofteng.com/products/data_rescue.php

Virtual Lab...

http://www.binarybiz.com/vlab/mac.php?PHPSESSID=48b398a7879fa364a82736a2b9bf955a

This one would require another HD with plenty of space to recover to.

You should use another Boot Disk or other Mac with this one in Target mode to do the recovery.

They have a free demo to see what it could recover.

on file recovery...

Trccharleshanks to Kurt Lang…

I had to recently recover a file I deleted (about a month ago). FileSalvage ran, but the way it accesses the drive to look for deleted items is incredibly slow. My version of Data Rescue was too old to run in Monterey. But it also suffers from the hours long process of examining a drive.

SubRosaSoft (FileSalvage) folded. If you go to subrosasoft.com, this is all you get. A very simple few lines of text:

Thank you to all of our customers over the years. SubRosaSoft has regretfully closed up shop. Inquiries regarding purchase of our domain or software assets may be directed to mhurlow@subrosasoft.com.

Data Rescue is still available, but is now subscription only. No way was I paying those prices for something I use less than once a year. That sent me on a search for something better.

I haven't tried Stellar's product, so I can't comment on that one. But I did test Disk Drill.

It'll do three free recoveries before you have to pay for it. But the kicker is the speed. I ran it and it said it was ready in less than 30 seconds (if it was even that long). Since every recovery software I had ever used before took a minimum of 8 hours to look through a 1 TB drive, I figured that couldn't be right. So I set if for a deep scan. Also done in less than 30 seconds. Easily found and recovered my file.

I don't know what methods their app uses to locate deleted items, but I didn't hesitate to purchase the full version for something that works that fast.