How would we do a better app store?

For me probably filters that are actually useful e.g. Top free apps with no ads

Whats annoying is that Google play has all the data to let you do this but they don't let you filter by if it contains ads or not.

Honestly, I'm pretty fine with them as-is as a user. Discoverability, rating, and feature description out-of-band, as in reading about them on the web, hearing about them on a podcast, seeing them on a friend's device, is good enough that I never feel any need to browse the store itself. As long as I can type in a name, download, install, and choose whether or not to auto-update, that's all I need. Apple's ability to manage and cancel subscriptions from one place, rather than needing to navigate a maze of different policies and procedures for each app individually, is also great.

I'm sure the experience can be improved for developers, but as a user, why should I care?

When you're talking about a store for "web apps," I guess I'm curious what that would even mean. Web apps don't need to be installed or updated. You just visit a URL in your browser and it's there. Every time you visit, the version that loads in your browser is up to date. What purpose does a store serve? Are you talking about something like IMDB for web apps but making production studios pay for listings and calling it a store?

Start with a capabilities based operating system, unlike phones and tablets with "permission management". This allows the user to decide exactly what resources the "app" gets at runtime, and it doesn't get any others.

At that point, it really can be whatever model you like, open source, or shareware, or closed source. If the operating system is doing it's job, then you can just run anything, and still be reasonably safe.

At that point, an "app store" is really just a catalog with ratings, etc.

I’m happy enough with the Apple App Store.

What I’m not interested in is living among a lot of app stores. I don‘t want to learn disparate rules for trial periods, refund policies, subscription renewal notices, etc.

That said, I want to feel like I own my hardware and OS and side-loading or native installs are required for that.

Define "better". For crooks, the best app store is the one that does absolutely no attempts to shoot down fake reviews and allows any app no matter what it really does.

As Broge said, I’d like a filter for free apps, no adds, no in-app purchases… basically filter and sort for everything.

Wondering: what’s your business model ?

f-droid.org