I thought 32GiB would be enough coming from 16, but nope, I found a new use case where it's too little.
Originally, I wanted to be able to run at least 2 VMs with 8GiB assigned at once.
But the new use case is a 4GiB RAM VM with 20GiB virtual disk stored in RAM (TMPFS). And that's not all that much.

I've also just been using it for random temporary things, as I am still paranoid about SSD wear. If I need to download an ISO just to burn it, there's no need to take, say, 3GiB from the SSD's lifespan, no matter how small that may seem.

But even if not used explicitly, it's still pretty useful for disk I/O cache. Especially with slow things like memory cards. At least for reading, for writing it's just annoying because I have no idea how much has already transferred, and neither can I safely stop it.

If you are willing to risk uncertainty, a modded 4090 might be better than a 5090 if you need VRAM. I think the Nvidia firmware signature was leaked for the 4090, so modders have been able to add twice the memory to individual cards and have it still work. 48 gigs apiece.

VRAM for VRAM, probably cheaper than a 5090 - if only because a 4090 is less powerful in all other respects.

Anyhow, if you decide to get more RAM, better do it soonish if you are American. Between the Canadian tariffs and the emergency oil stockpile running dry around half a year, prices are set to climb further. This whole situation sucks.