I am suprised they are already gone. Unless you have a very specific use case, these are just too expensive per GB. For ZFS slog/l2arc most enterprise grade NVMe devices will be plenty.
I use them primarily to host databases, initially for work, but eventually realized I had plenty of free space for my tiny home lab DBs as well - mostly postgres, though the work-related testing ive been doing has more recently had me testing converting all my pg DBs over to cockroach... See how "postgres compliant" it actually is, and if I'm lucky, perhaps I can just move all my postgres DBs over to it. We'll see, fingers crossed!
Its done a world of good when it came to application performance for nextcloud, forgejo/gitea, and several others. I dont really need tons of capacity for such things (I think my nextcloud DB is maaaybe 7-8GB? lolol), but the latency being as low as possible for what *is* actually used has been fantastic. Its at least as performant as most vendors cloud offerings at this point (well, the UI is... can't compete with their bandwidth hehe), which has made it easier for me to convince the wife (etc) to use it over things like google drive, icloud, and so on.
Other than that, i threw the boot volumes for a couple OS's to tinker with... along with a boot volume for a gaming VM, because why not I guess lol
I dont think its the $/GB that had them flying off the shelf, so much as the cost being low enough that those with any other niche low latency applications like those above also probably just figured "why not" - that'd be my guess at least. Its where my mind went anyway.