Apple has not 'nixed' macOS Intel. In fact, they have stated that macOS Intel will be supported for 'many more years to come'. That is likely not 8-10 years into the future. But it is also extremely likely not 1-2. There are 100M Intel Macs out there. They still work reasonably well. This isn't like the 2006 transition. Two major different factors in play.
1. An installed base of approximately 100M versus of about 30-40M. It is 2x to 3x as big of an inertia factor this time. Sales of M-series Macs are quite healthy, but there is no stampede off of Intel macs. ( as usual Apple bragged about huge chunk of M-series buyers being "new to Mac" buyers. All sales to those folks does nothing to drop the Intel install base count). It will take several years to work that down. And longer than it did for the PPC or x86 transition.
2. The transition from PPC-> x86 happened in about 18 months. Apple has taken sustainably longer this time. September 2022 Apple will probably still Intel models still for active sale. As long as they are selling Intel models brand new there is no way they can turn around and kill in a "year or two' without a huge public debacle (and likely class action suit).
Apple might do a "sneak peak" of a Mac Pro at WWDC but pretty doubtful they will ship anything before late Fall.
"... Products are considered vintage when Apple stopped distributing them for sale more than 5 and less than 7 years ago. ..."
https://support.apple.com/en-us/HT201624
The countdown to 'de-support" for Apple starts when the stop selling something. They are still selling so the countdown clock hasn't even started. Cannot possibly be 'nixed' when the clock isn't even running.
3. Apple didn't own Rosetta on the first transition. Apple rebadged Transitive's tech . Which means they had to pay per machine sold. IBM bought Transitive right around the time Apple dropped macOS PPC. Apple wasn't going to get lower terms out of IBM ( not going to beat them up at the lawyer table. ).
This time Apple owns their Rosetta tech. It works and not likely they are gong to spend more R&D fixing bugs or extending the emulation coverage. So it costs not much to keep it around. In 10 years they may have left it in zombie status for so long that can't easily fix a critical bug even if they wanted to. So it won't stay around forever, but die in a year or two.. very probably not. ( they spent a ton of money making (there are augments even down to hardware level for this so it was in no way shape or form "cheap" . They need to make the money back as a feature for sale. )
Better at what? Around the PPC->x86 transition was the point at which Mac laptop sales started to dominate desktop sales.
Power6 and Power7 where better server chips. They were not better iMac or laptop chips. Those were and still are the bulk of Macs sales. The M1 mini is probably doing better nowl as a contributor to overall unit sales, but that that just skews the point even more.
Apple used their own I/O chip as a 'firmware dongle' on Macs. Apple did relatively little to promote the general PPC ecosystem breadth and growth. So no it wasn't surprising macOS didn't run elsewhere. That was a contributing factor. Apple didn't want to pay what it cost to be best in class for the segment their systems are/were in. So IBM skews Power to what paid the bills (their server boxes with Power and Z-series ). Money talks.
That's a fairly long time. That might run into major problems before the macOS Intel updates run out. When all the pre-T2 macs are put onto the obsolete list there is chance they'll hook booting to having a Apple T2 present. At that point in bad shape ( and may need some pretty hefty hackery). More likely most folks will just stop on that last non-T2-only version and declare it good enough to run forever.
The other big problem is likely lack of future GPU drivers. 5-6 year from now running 6-7 year old GPUs isn't going to be very attractive to most hackintosh users.