But imagine if Windows worked the way Android does. You buy a Dell Windows laptop and then you receive all your OS updates directly from Dell, they limit you to only 2 years of updates (if that), and put some bloated skin over the whole OS.
I don't know why Android users accept this.
Biggest advantage is that it's a pure Android with no bloatware from the manufacturer. Also you get a guarantee IIRC to have at least two versions upgrades for the phone (my Xiaomi came with Android 8, so 10 should be the last one), and most of all security updates.
All iOS is pure iOS. That’s the selling point for me, at least.
I don’t want iOS on my random experimental project laptop, for that I have Linux or windows, or vms. But, cellphones are not something I need to hack around on.
You can also choose to jailbreak an Apple device if you really want to be unpure, and luckily doing so won't prevent you from updating your phone in the future.
Different strokes for different folks. I like having the ability to sideload apps and flash a different OS to my phone
Also what bothers me about Android devices: I got a Galaxy S8 to do development for work, and not all manufacturers are created equal in updates of course; IIRC I waited almost a full year after the Google flagships to receive Android 9 — in fact I think I got Android 8 around the time Android 9 came out.