"The web is the first truly cross-platform development environment."
...and then talked a bit about how it's open (yeah, ok, sure), and then you said it's not really a good application development environment (obviously).
I'm saying, your entire premise is wrong: it isn't an application development environment, any more than a box of legos is a "housing development environment". People have built houses out of legos, but that doesn't make "lego" a building material. It's a big, messy, nasty hack.
The fact that it's "open" is a non-sequitur response to "it's the wrong tool for the job", which is what the OP (and I, and elviejo) are arguing. It's also not a legitimate response to argue that any re-thinking of the model has to come from a company, or otherwise not be "open".
The reason that web apps happened is because web apps started as a hack. That doesn't mean we can't change the paradigm, but to do that, we have to stop defending the current model.
(Realistically, the reason I'm getting downvoted probably has more to do with my willingness to call out React as a pile of garbage than with the substance of the greater argument. C'est la vie...it's actually pretty amusing to watch the comment fluctuate between -3 and +3...)