Off the top of my head? Google Photos is actually usable, there are many options for game streaming and emulation, PWAs work, Termux (think iSH but significantly faster) works, transparently proxying phone calls through Google Voice or other services works, browser extensions work, on-device system-wide ad-blocking is available, and there are multiple options for driving infotainment (including Android Auto) without a head unit in the car. It is enough of a gap that I have never considered using an iOS device even though they're offered to me for free.

Some major pieces that are missing from both are the ability for user-installed apps to auto-update without using the system app stores and the ability for a user-installed app to process call audio.

You're looking at it.