If Jim Keller hadn't gone back to help AMD, and if Dr. Lisa Su hadn't decided to take on that challenge, we'd likely be stuck in an era of processor Dark Ages, OR, Apple and their Apple Silicon line of processors would be even more attractive than they already are.
Intel gained an unfair advantage and built their reputation by taking shortcuts with security. The FX series weren't marvels of design engineering, but they weren't nearly as behind the performance curve as customers were deceived into thinking.
AMD's processors, while not fast, did none of those things and were cheap. I guess that buys you a lot of good will when Intel's still charging 300 dollars for CPUs that wouldn't beat a 2500K at 4.6GHz until several years down the line.
And "have to replace the motherboard along with the CPU" is the exact thing we're talking about here: there was no technical reason for Intel to make the earlier boards incompatible, they did it just because they could. Not that there was ever really a reason to upgrade beyond "buy the cheapest K series, set multiplier to 46-48x, done", but even if you wanted to, you couldn't.
It was an anti-consumer practice and said consumers never forget it (not that most tech channels don't provide active reminders of it). And those people are who everyone else asks when "I'm getting a new computer", they say "buy the competitor's product", and the rest is history.