The "everyone does it too" argument quickly breaks down if there's no alternative for you platform. On Android, you can easily sideload others stores, on PC you can use Epic Store or one of many others, but iOS has no other options.
How about Xbox or PlayStation? Those have both virtual as well as physical app stores in the form of game disks. There’s no way to avoid the lic fees in these platforms either.
The "everyone does it" is true in console gaming though, so the argument actually could apply them. Apple is the only mobile platform that it doesn't do the same as others (Android)