About five years ago I bought my husband a Samsung 840 1TB SSD. It's been actively used pretty much everyday since it's been installed, which is no small task as my husband is a video editor. It occurred to me the other day that SSDs can't last forever so I booted up the Samsung magician software which said the drive status was still "good" but that he had racked up 65TBs worth of data usage on this drive. While I'm not too concerned that it will imminently drop dead (that's what back ups are for) what do you think you think would be a sensible time to make the swap to a new drive? In the same way you change the tires on your car after "x" amount of time or wear.
If I do put the drive out for pasture while it still has some life in it I could sell it to the likes of "CEX" (after data wiping it) and recoup some cash.
I look forward to hearing your input