So you mean to say that you detach the main unit of the Surface Book and use it as a tablet, right? Well, yes, obviously, but that's not a laptop touchscreen anymore, no?

As for laptops and processing power, what you claim is true for all laptops, Apple and Windows-based alike. But nobody in their right minds would buy e.g. a fully-loaded M1 Max MacBook Pro unless his/her workloads can make us of that extra power. MacBooks are not suitable for gaming, as are powerful Windows laptops, so they are tools. As tools per se, the best MacBooks are better than most Windows laptops for productivity and creative work. Sad but true.

What you claim about market share is true because Apple liked to play that game in that specific way, that is sell overpriced pro hardware with huge profit margins instead of trying to have Macs for every type of consumer. That is already changing with the M1 and its successors (just look at what happened with the Mac Studio - a first for Apple).

Corporations are only a part of that equation. If more consumers start buying more Apple machines, and they will, then macOS market share will start changing. Apple does not need to get more than 20% of that in order to be extremely profitable either. The M1/M2 chips do have the potential to bring about change. I truly think so.