The machine I had before this had 4 GB, lol. That's why I put so much of the budget into RAM when I built this one.
I mean, you can never have too much ram.
But if you don't use it in its entirety, it is kind of useless.
192GB is way to big to be used as a cache
However, you probably could run some of the huge language models
You are underestimating writebacks. You won't use that much on a normal filesystem and with ZFS you will only use that with bigger amounts of data