This is a very interesting, but it doesn't explain why companies push so hard to download their apps. It's even contradictory: since it seems users want apps so much, there should be no need to push them.
Then there’s a measurement element where app installs became an important KPI around the time ad blocking became more popular and interfered with detailed website engagement tracking, creating a self-fulfilling kind of thing.
On top of this I think another factor is that many websites are in terrible shape, super bloated by ten thousand tracking pixels and third party snippets added willy nilly by marketing teams using Tag Manager, so apps benefit from gatekeeping that bloat to a degree.