They're also market-locked. If you have so little ability to function outside of an app, you become incredibly resistant to moving from one to another unless it's identical, and you're incapable of using marginally more complex things.

It also gives immense market control to the app stores, have been allowed to exist mostly unregulated. Thankfully that might be changing.

When everyone must be spoon-fed, that makes the only company selling the spoons insanely wealthy and powerful.

It's also going to have a degrading effect on popular software overtime. When the only financially viable thing is to make apps for the masses, you are not incentivized to make something extraordinary.

Compare Apple Music to iTunes, just on a software level. Just on the sheet number of things you can do with iTunes, all the nobs and levers, all the abilities it grants a user willing to use it to its max potential. At some point, it no longer became viable to create an excellent piece of software, because most people have no skills or patience or desire to use it.

So you start making things that don't empower the user, instead you make things that treat them like children, and your products get stupid.