I only remembered a couple CompUSAs, Circuit City, and Best Buy selling computers growing up. I don't remember visiting any independent computer stores in the mid 90s.
But talking to those in my parents' generation, most of them bought their computers from some local small shop (and sometimes went back there for computer training!).
I count St. Louis lucky for at least having a Micro Center today, otherwise all my parts would have to come from online stores.
I remember in the mid to late 90's, you could build a computer for someone and walk away with enough for an upgraded system for yourself. Of course the churn on performance was very real. IIRC, 1992 maxed out with a 486 DX2 @66mhz. Around 2000 we crossed the 1ghz mark from both Intel and AMD. We went from OG Doom that couldn't cut it full screen, to Half Life and Quake 3 Arena on Voodoo 3 and early NVidia cards.
That stopped being effective sometime before 2010. Instead I'd recommend buying a decent enough machine and sticking a graphics card in it.
4th gen Core series was the longest I'd held onto a single PC (close to 5 years total for a 4790K). I did a mid-cycle gpu and nvme upgrade and that was it. I bumped to a 3950X/5950X and now 9950X since... AM3 is really the first socket in a long time I'd done an in-place upgrade for any CPU. My daughter's Ryzen 2400 to a 5000 series, and my own build from a 3600 -> 3950X -> 5950X... the 3600 was a placeholder as I couldn't get a 3950X for a few months.
I couldn't even name half the CPUs I ran from 1998 to 2005 or so... it was such a blur of upgrades every 6-12 months... I'd upgrade my computer, my wife's, my son's... etc. Then, things just completely stagnated... I mean there's been progress, but it's over the course of years, not seeing 2-3x in under a year.
FWIW, I haven't been to the Phoenix Microcenter yet, mostly in that I'm afraid of how much I might otherwise spend there.
A few years later my mom finally let us get one with buffer underrun protection (and some multiplier on the write speed) so I could make mix CDs with music off Napster for my girlfriend and life was good.
She still listens to it when working.
Now add money they were making on those mandatory dialup subscriptions and you got a money printer.