bzr lost because it was poorly-architected, infuriatingly slow, and kept changing its repository storage format trying (and failing) to narrow the gap with Mercurial and Git performance. Or, at least that's why I gave up on it, well before GitHub really took off and crushed the remaining competition.
For my own sanity I began avoiding Canonical's software years ago, but to me they always built stuff with shiny UI that demoed well but with performance seemingly a distant afterthought. Their software aspirations always seemed much larger than the engineering resources/chops/time they were willing to invest.
I don't think it's a hardware problem. After a few days/weeks of uptime, coreaudiod sometimes gets into a state where, regardless of output volume, it glitches and pops periodically until you force-quit it. It's like the daemon's internal state degrades such that it's just on the edge of able to feed audio buffers to the hardware fast enough, and then all bets are off as to whether other system load will tip it over into glitching.
Things seem worse if you have and switch between multiple audio devices. I filed a Radar on this (or a very similar bug) many OS releases ago that's still open with no feedback. But "restart your computer" also solves the problem, whether or not you follow the other placebo troubleshooting nonsense.
Yeah. To me it looks like macOS goes so deep into sleep it disconnects the external display. On wake, the system rediscovers the external and resizes the desktop across both displays. With a bunch of apps/windows open, half your apps simultaneously resizing all their windows can peg all CPU cores for a number of seconds.
(It's still way faster than the same set of apps on an Intel Mac laptop, where it could sometimes take on the order of 30 seconds to get to a usable desktop after a long sleep. On Intel Macs it seemed more obvious that the GPU was the bottleneck)
The original Rosetta was also a licensed technology that (presumably) cost Apple a pretty penny. If Rosetta 2 is all in-house tech, that probably bodes well for sticking around longer than the original.