It's true that the average computing device is turning into an appliance (is it a bad thing?), but it also appears the options for DIY are ever-expanding.
Yes, for those of us who mostly want the appliance, but sometimes want to tweak it. I don't want to have to build a system from the ground up to get my desired experience if it's 98% the same as the appliance would have been out of the box; I'd much rather start from the appliance and just change the 2%.
As Strong Bad might say, we have too much appliance in our computers, and too much computer in our appliances.
I know of one company that has a few "desktops" that are Pi4 and I've seen loads of them powering "active terminals" - like in-store menu and office status screens. Gotta start somewhere. Special case and move towards general case (some call it crossing the chasm)