That sounds highly disingenuous. F-Droid appears to have over 8 million downloads[0]. Amazon's store is probably well patronized too (and they seem to have good deals on paid apps). I'm sure there's some piracy, but I don't think it's that prevalent (at least not in the US). Either way, as a user, I'd rather be on a platform that is open enough that piracy is possible.
[0]: https://gitlab.com/fdroid/fdroiddata/blob/master/stats/total...