[sh3rl0ck]

It doesn't "require" a launcher at all; but the people have the freedom to change theirs.

Kinda like MacOS users only have Aqua, whereas Linux has a lot of DEs, the choice of which is entirely handed to the user.

[toast0]

Android without a launcher would be pretty weird.

You could use the AOSP launcher, or whatever your phone maker installs instead. I don't, because phone makers seem to really want to push an unremovable search bar that I don't want. And swipe left to see a totally confusing screen I also don't want.