Are Facebook and Instagram unusable on mobile Safari, which bypasses the App Store? (I haven't used FB/Insta for years, so I'm not asking a rhetorical question here: I really don't know and I'm genuinely curious.) I do know that viable mobile browser video games that bypass the App Stores are currently impossible to do on both mobile Safari and Android Chrome because I recently tried. Dark patterns are employed, including adding a typical 300ms audio latency to the Web Audio API on Android Chrome[1], and making WebGL perform terrible on iOS Safari, preventing WebGL from going full screen, preventing accelerometer/gyro input "for privacy reasons" etc.

[1] Superpowered Android audio latency test database shows how awful Android web audio latency is:

https://superpowered.com/latency