It's funny.
I've had 64GB in my main machine since ~2014.
That was when I decommissioned my old consumer hardware based server (AMD FX 8350). It was maxed out with 32GB of DDR3 RAM.
When I decommissioned it, I had all of this RAM I didn't know what to do with until I remembered that my workstation board (which already had 32GB of RAM in it) had four empty RAM slots in it.
Through random luck the RAM in the server was the same manufacturer (and very close timings) as compared to what was already in the workstation, so I was able to just pop it in. (X79 was quad channel, and mytt board had 8 slots in total)
These days using two sticks of RAM per channel may cause heartache, but apparently it didn't back then (or I was just lucky).
Anyway, the result was that I had 64GB of RAM in the desktop back in 2014, which was a pretty insane amount a decade ago. Most "gamer" machines had 4GB or 8GB if memory serves.
And since I al allergic to downgrades, I mimicked the 64GB when I upgraded to the Threadripper in 2019. By then it was way less exotic, but still kind of a lot, and way more than I really needed.
Now, 5 years later maybe 64GB will finally be useful?
I am actually considering getting rid of the workstation, and just running it as a VM on my server. If I do, I am going to build a special purpose PC just for games. My very early phase plans included going with 48GB of DDR5 RAM in that machine (2x24GB) but maybe I am going to have to change it up a little
Definitely time to go 64GB I guess. Maybe even time to stay ahead of the curve and go up to 96GB?