Out of interest (now that you have it working) can you see how much wear your ssd’s have experienced?
If you have 2x M.2 drives installed and one is the boot drive then you can compare total writes.
Which drive is MSFS2020 installed to?
Which drive is the rolling cache writing to?
Do you have a manual cache?
Is the pagefile location at its default? (C: drive)
Normally it should take a reasonably long time to kill a NAND SSD. They do wear, but it would take a few years of 100Gb per day type activity.
However, as you note, if the pagefile has been going crazy because of MSFS2020, you are constantly writing to the rolling cache and frequent large updates from Asobo you should see extra wear on one drive if it’s carrying all that load.
In terms of what caused the fault? It’s hard to say without more data.