So how did it die? Very suddenly, no warning, so my understanding of hardware seems to indicate the fault was most likely from the drives controller because I've seen dying SSD's before and they often have some very tell-tale signs that make it easy to get data off the drive before it's too late - not so this time.
My Laptops cooling system started running at about half speed when I woke it from suspend the second time this morning. For this machine, a 9 year old Lenovo T560, that's a little odd because running MX, it's normally whisper quiet with the fan barely ticking over and only becoming audible when it's doing some heavy lifting. I checked my emails and let the updates run while I made a coffee, when I returned to it, the fan was still running at about half mast as it was earlier so I thought I'd reboot in case there was a memory leak or a dirty memory issue, as it used to have before I addressed the issue.
My Laptop booted to the Lenovo logo and stopped dead, nothing would make it go past it, could not boot into BIOS or do anything with it. Resetting it by pressing the pin-hole battery disconnect button made no difference so I cracked it open, removed the drive and the machine was happy to boot, so I knew the drive was the failure point. When I tried to read the drive from a USB drive enclosure, every machine I plugged it into just could not read the drive and watching the kernel messages revealed the kernel could not determine anything about the drive, it was as if it did not exist, other than pulling a few volts from the USB port. It was then I reaslised my last backup was 3 weeks ago and I had neglected to take them after doing my financial years end for 31st March - big oops.
All in all, only a minor loss as I retrieved much from emails I keep stored on my hosts mail server. Recalling I purchased this drive about 5 years ago, I looked up the invoice and it had 2 months left of its 5 year warranty, so I get to do it again for next to no financial outlay, other than a few dollars for a new 250GB SSD from stock to get the machine running again and a courier fee to return the dead drive. Home is encrypted, Windows had no value, so I have next to no concerns if they can get it to read, which I think is highly unlikely. I copied my 3 week old personal snapshot from my backup drive to my ventoy boot USB, booted into my snapshot, pulled in the updates while partitioning the new drive, run the installer and reboot. I then selectively rsync'd the minimal data needed to run the machine as if nothing ever happened and get on with it.
I believe the SSD failure was just pure bad luck, not a case of having worn out because I kept a close eye on its condition and it was nowhere near a point of concern showing 89 percent endurance remaining last time I checked. I have to admit, my last 3 weeks have been very busy in my work-from-home business with some new clients so I have slipped up with my backups, that's my bad, but overall a good enough result through having a good backup strategy, even when I missed one
At one point my brand new 1TB SSD backup appeared to not be working, so I was thinking I was in the worst possible scenario, turns out it was debris in the USB port, whew!