And in the proposed 10 years being discussed here, there's no reason to believe locally-installed applications won't have exceeded browser sandboxing capabilities, let alone caught up.
Meanwhile, the web sandbox is actively deteriorating specifically because frontend developers want to do the things locally-installed applications can do.
> Nobody should be installing Facebook, Twitter, or Reddit on their phone.
Not at the current state of native app deployment, no, but that's improving rapidly and substantially, especially in the mobile space. Also: the vast majority of users are doing that anyway, so it's worth investing the time and energy into being able to sandbox apps without needing an entire HTML + CSS + JS engine/stack to do it (and indeed, both Google and Apple have made significant strides on that front in the last 10 years, though there's certainly still room for improvement).
> The unfortunate, horrible problem, is that running code we don't trust is gonna be necessary, no matter what world we move to.
Yes, but at least with a locally-installed app, I'm explicitly opting into that app existing and running on my device. This on its own will at least somewhat cut down on the amount of untrustworthy code running on my system.
Yes, I can do the same thing for a website's JS code (and indeed do so), but it's asinine that I need Javascript enabled to read a blog post or post to social media or do the myriad number of other things that are theoretically and practically possible with server-side processing exclusively.
> Of course integration and app performance suffers on the web. But frankly, neither of those are more important than sandboxing.
No, but sandboxing - again - is a problem that can (and almost certainly will) be solved within the next decade, at which point integration and performance benefits will make local app installation even more attractive than it already is.
