Like I say - I really don't know what the state of gaming is today. I see people on Ars in discussions from time to time, but personally I'm not into gaming since I sold my Amiga stuff years ago. That said, I was never a serious gamer.
And while years ago I was somewhat into building/modifying PCs, it has been a long time since that interested me. And I never was into serious builds such as over clocking, liquid cooling and fancy cases. I will say some of it is impressive, but I don't have a desire for, or a use case for, building a such an impressive PC. I do understand building PC's as a hobby, but for me those days are long past.
And admittedly I'm mainly a Mac person. I have a couple of PCs, but have thrown out all but one and a Windows laptop I have for travel. It's pretty much stripped down for travel and a "throw away" that if lost or stolen (or confiscated at a border) isn't an issue - I don't keep anything of significance on it. All I have to remember is the URL and password to access my home Mac in screen sharing mode.
As to the original post, I believe the trend away from desktop boxes is continuing, at least anecdotally. A lot of older people I know don't have anything more than a tablet like an iPad. Most of what they use it for is email and stuff like that. I personally do have an old iPad but I rarely use it because I use my old 2013 iMac which is on my desk. And while in years past I upgraded about every 4 years, these days I just don't have a use case, or significant desire, to upgrade.
This is from 2018 but has some interesting thoughts:
Is the PC Desktop Dead? 2018 Article