The browser is an extremely poor medium to deliver applications. It works, but barely, is a huge resource hog, fragile and it breaks way too often due to a lack of backwards compatibility between browser versions of the same manufacturer. I have a small app that I support and it's been fun to get it to work in the browser (instant cross platform support was indeed the driver) but the experience is still sub-par compared to what I could do on a local application.
You could have clicked on my profile to find the app that you're criticizing unfairly. It does not use react, but it uses pure html5,css,js, it is extremely fast and light. And yet, there are things that it can not do simply because it runs in the browser, which is a poor operating system for a hard real time program to run under.
I did not criticize your app. I offered that your blanket statement that "The browser is an extremely poor medium to deliver applications" does not comport with my experience. And it looks like I nailed it, too. It is the nature of your application. Had you said "the browser does not offer a real time API which I need for my application", there would have been nothing to say. This is obviously true. Even native desktop apps provide an inadequate environment for "hard RT". So I suspect that is also not a true requirement, either.
Well, there are apps that you can only do native, not in a browser, we agree on that. But I also think that the browser is actually providing a very compelling standard OS with batteries included for many kinds of applications, and now there is even webGPU. I am currently building a local-first interactive theorem prover with built-in IDE as a PWA, in TypeScript, and you have really cool tools you can use as a foundation for something like this, such as ProseMirror and IndexedDB. Of course the raw prover can also be run from the command line via node. Claude Code is also very useful in this environment. Yes, different browsers are an issue, but so much works on all modern ones.
Unfortunately, I think all these things are externalities - or at least, areas that don't impact revenue enough to get companies to change.
I too wish that software would be efficient, robust and long-lasting. But it seems that most people don't care about this enough (compared to other factors) to force change. (Alternatively, they are locked in to platforms they don't like to use.)