Many people want the build to be in Docker to.

I personally don't -- I publish on the host build agent and just Dockerize the publish directory

I'd like to point out elemenatary OS as a counter-example:

They have consistently provided a high level SDK for their OS. With elementary OS 6, they moved their high level SDK to using flatpak (not flathub) as a distribution mechanism.

That's probably because they are a very niche OS, while flatpak seems to be gaining in popularity.

The apps that are "broken" are apps that are not "Flatpak native", so assume they have full write access to ~

Flatpak aware apps (like the ones I develop, or any on elementary OS since flatpak is the native packaging format there) tend to just work.

It's not true they assume full write access to ~, they just don't propagate they limitation of a constricted choise of paths in their GUIs. Because they isn't a way to do that, GUI toolkits don't really provide a way to clearly communicate you can only save/open in a specific dir.

I live in a "large city" (suburbs in a top 10 metro in the US) and $800k gets you a mansion here still. My 3400 sq ft house is worth ~$350k for a "almost new build" (I had it built in 2015) 6 bed / 4 bath, gigabit fiber, swimming pool / soccer field in the community, great schools, shopping, etc..

I'm also a Principal SWE and my salary is well below $200k, though there are years with bonuses, etc.. that I reach $200k

So you live in in an area that have massive urban sprawl and no bounding area driving up the costs (like say San Francisco or Toronto or London). Good for you and your urban sprawl McMansion existence (nothing wrong with it). But just because you can buy a mansion where you live for 800k doesn't mean that for millions of us 1 million dollars will get us a shitty house in a shitty area.