Which apps? 50% of the time is spent in their most popular app, and 97% of the time is spent in their 10 most popular apps. Considering that the top spots are taken by fb/instagram/whatever, what's left for discovery? I'd argue that the 10% spent on the browser is 99% of the discovery that users do, probably via links from their favourite apps.
It seems the app space is way more overcrowded than the web.
It was much easier for me to write without the limitations of the browser and the web APIs getting in my way. Apple's APIs have a few warts, too, of course, but they are easier to work around.
I do as well, and that is what I do for side projects, however 100% of my professional work regarding mobile devices can be done in 100% mobile Web.
They are just plain CRUD apps for accessing services, easily done by sequences of forms.
We just don't do React and friends, rather SSR with minimal JavaScript for dynamic stuff.
I seriously doubt that, if my 8 core macbookpro has issues with half of the web (event my own react projects of sizable complexity start to have issues), doubt mobile devices don't. And I honestly can't speak for Android, but being both and iOS and React developer, iOS performance in pretty much anything compared to React is amazing.
Also, the second part, I have been doing research lately, and while the dev.to or HN crowd says they visit the mobile websites, market research shows that people spend around 90% of their time in apps versus 10% in mobile web, so seem users find them relevant.
I know developers don't like 'closed' systems and love the web, but I (and most people I know) personally prefer a app over a mobile experience 99% of the time.