Earlier quoted context omitted.
You can install from other stores (AnkiDroid is on F-Droid, for example), or from direct file download on Android already. The problem is rather thay most users just use the store preinstalled on their phone as part of Google's deal with OEMs to bundle Google Play Services. So either you follow Google's rules, or you lose all the users who don't want to leave the walled garden, even though they can.
When do we stop this instinctive response of "well you can still do it in an only slightly convoluted way" everytime a corporate does something bad. Windows added ads - well you can disable them, if you don't like it. Chrome brought up mv3 - well you can still use mv2, it is only optional. Reddit locking subreddits behind login wall - well there's always old.reddit Android moving everything to playstore - there's alw…
And the menacing messages of installed something from F-Droid. My mother would never do it. Even my programmers colleagues usually don't do it.