Ever since 2011, to this date, the CPU industry has gotten interesting, with AMD's effective dropping off the face of the performance charts, when Intel made their platform a bit pointless with Sandy Bridge.
Now that AMD is back in the game, the performance balancing act is going to get interesting, especially with the looming event of the end of Moore's law, where CPU manufacturers will have to start to get more creative.
I've never actually owned a Cyrix chip, and to my knowledge I have never owned an x86 CPU not made by AMD or Intel (I might have and just not know it in some sort of embedded application).
You're right. AMD have been on the back-burner for a while, with both CPUs and GPUs. These days I find (especially with their GPUs) the slight performance gain isn't worth the extra pain and suffering in terms of component failure and trying to keep the damn things "cool enough". It takes a lot to cool a server rack, let alone a whole room.
It's always been a cat and mouse game between AMD and Intel and I think we haven't seen the end of it even as we approach the "Moore's Law limit". You'll just start seeing multi-processor boards becoming even more popular than they have in recent years and I/O becoming faster and faster such as NVMe (developed by Intel).
I owned a few Cyrix-based machines back in the day. They were nothing to write home about in terms of performance but they were reasonably stable and ran far cooler than the AMD chips of the day. When you were relying on a pissy little heatsink and fan, this was important.