No. Not that I condone it but I at least get why 32X/SEGA CD. PCE CD and such were done. They did things with the extra power that the base console could not do, from audio to more going on on screen and backgrounds. Scrolling and such. Even limited 3D games and FMV games. So, at least the games took advantage of the new hardware that wasn't possible before. Technology was advancing at an accelerated rate in the 90s. PS5 Pro is not that special. You need a digital foundry video to zoom in on a game and spend 5 minutes explaining a minute change in a background. It's slightly smoother. Yup, that's worth 200 more dollars lol. We're at diminishing returns, and the PS5 Pro is practically useless if you already have a PS5.

It would be idiotic for Sony to release games that would only work on the Pro models. They are just mid gen boosts, bridges towards the next gen.
BC is very important nowadays, even between gens.

I can't even imagine a game that would justify something like that. I mean, is there any game that can't be scaled down enough to run perfectly fine on the base consoles? We're not in the age of highly specialized hardware anymore with developers working their asses off in Assembler to make engines solely for a single game. It's mostly stuff off the shelf. Unity, Unreal Engine and stuff like that, and those don't have any problem at all running on a Series S. Hell, you can run most modern PC games on 10 year old hardware if you just pull the sliders to the left.

I don't like the idea and I see no reason at all why it should happen in this day and age.

You are absolutely correct about the user base issue, 100%. But handhelds were super cheap, and different from home consoles. They played by different rules.

Nintendo was too lazy or cheap to get even SNES games emulated and running on 3DS/2DS. For some reason, it needed the more powerful hardware.

But New 3DS didn't even come with a charger, so it's not surprising.