They might just replace their phone a lot. Some people do that.

Actually, despite the common wisdom that Apple users are always getting the latest thing and just can't wait to give Apple more money at every opportunity, every person I've known who replaced their phone about annually to chase whatever the just-released flagship phone was so they can always have the shiniest thing, has been an Android user. Though, to be fair, I've also known plenty of Android users who don't do that. I've just not yet seen an Apple user behave that way (but I'm sure some do). I think this has something to do with Android fans having more overlap with computer hardware enthusiasts in general, than Apple fans do.

I've also known a few Android users who get a new phone every year because they think the next $200 phone won't suck just as much as the last one did. And that, sure, is kinda their own fault.