Insert inevitable reference to "the Birth and Death of Javascript" but native platforms should be copying the web more in general. The DOM is just structured CLI output, with all of the advantages that CLIs have. Seriously, as a user nearly every native app on my machine ought to (in a better world) be rendering its interface to a structured text format that I can inspect and modify on the fly and pipe into other applications or dynamically restyle as I see fit. Because of that structure, most web-apps can be extended arbitrarily with user extensions. The sandboxing on the web is... okay it's not great, but it's better than what anybody else is doing. The delivery platform for apps is better specifically because the sandboxing is better, which allows me to try out apps quickly without giving them a lot of unnecessary access to my computer.
People are building apps in the browser because browsers offer capabilities that native operating systems don't offer. The few platforms where browser dominance doesn't hold true (iOS, Android) largely maintain native dominance by severely limiting what web browsers can do. That's the wrong way to move forward; offer a native experience that's as good as the web and people won't need to build apps on the web.
Even just good application sandboxing alone would be a good start, and yet whenever something like Flatpak tries to make progress in that direction, people are constantly complaining about it and explaining that sandboxing is the wrong way to approach app security. It's not really surprising then that people look at that discussion and take away from it that maybe the desktop isn't a good fit for their app.
----
My only critique of the webGPU direction is people bypassing the DOM, which... is usually the result of native developers and native frameworks trying to bring native development patterns to the web instead of rallying behind the idea of user-inspectable pure-text interfaces in the DOM. In that regard, and very specifically in that regard, I do kind of agree that the web is becoming too much like a native operating system. In the sense that it is repeating the same exact mistakes that native operating systems made.
But in regards to people just generally building apps in browsers... good. Honestly, progressive web apps are a safer, more user-respecting way to deliver functionality than native OSes are.