It's enough proof for me, at least.
Native apps continue to exist for areas where browser APIs aren't sufficient yet, that's true. But those will get replaced once a sufficient API supports it
Just because business see that it's cheaper does not make it the better option.
It could also be said that it's a feature that the app does not 100% follow the native UI as the experience will be the same irrespective of which OS you are on.
Is it a feature, that MS Teams (as a default setting) does not use native notifications on OS X? As a user, I have to disable two notifications now, because one does ignore the system setting. I don't know how to sell that "feature"... Imagine having many apps with each having it's own notification setting, layout and appereance.. That's hardly an improvement to the status quo.
There’s factors occluding this though I think-the JS/web stack has had millions of dollars of investment thrown at it by parties with a vested interest in seeing it succeed, so a lot of UX issues and friction points have been smoothed over as much as possible.
The wider native UI ecosystem hasn’t had the same investment, so I’m not surprised it’s superficially “easier” for devs to thrash out a UI with web tooling. Doesn’t mean the resulting application is actually any better though.
Web apps are dreadful, regularly lock up, and are an active step back in computing. But hey, if your startup can spew out a shitty app much faster, good for you.
I actually prefer to run MS Teams in a browser tab instead of installing it to my computer. Same with Slack or Zoom. I'm not losing much since their core functionality relies on an internet connection. Full-blooded browsers are also more likely to stay up to date than the bundled Chromium build, and I can enjoy the peace of mind from a modern browser sandbox.
IMHO, replacing something != proving something. We may have replaced desktop apps with browser-based apps somewhere, but that does not prove anything. I'm looking at a lot of professional software, that just won't perform as a browser app (or work at all) in the near future. And then I look at a lot of crap browser-based software (like MS Teams) that makes me wonder whether this was actually an advancement, because it absolutely does not feel like it. It's UX is just miserable and so slow.