To imagine that the transition from ppc to x86 is remotely comparable to a present-day x86-to-ARM transition is utterly absurd. Basically everything has changed: Hardware architectures, software architectures, OS design, etc. The amount of software out there for x86 macs is massive and end users are going to expect all that stuff to work (even if they'll grumble and accept it when Apple tells them that only 50% of it will work). You're also having to maintain compatibility with a massive set of third party hardware used by creatives, developers and enthusiasts - are you gonna run those drivers in an emulator? In kernel mode?

This would be an undertaking beyond any past one, because in the past computers were much simpler and Apple controlled a bigger part of the picture. Now they're shipping elaborate GPUs and hardware stacks that mash together chips from various vendors and there's a ton of third party hardware and software all working on top of it. If they don't keep most of that working users won't stand for it. Something like "we need to get AMD or NVIDIA to provide us a top-tier video driver for the Axx instruction set and convince them not to demand a king's ransom for it" would not have been an obstacle in the PPC days but it's unavoidable now unless they want to ship their own GPU too (which they could do, but again, compatibility)

Be Inc went belly up because of MS anti-competitive practices. Vendors would get a discount if they shipped only windows computers