npub1lj756j70nykyqjtz5hfs43gkzyvzjpq36lt9u2qxxrp9jtqws5mqkdzczx (npub1lj7…zczx) It's just not an environment that encourages it. Mac users have had a long history of paid software, whereas the non-Apple environment has had a longer history of shareware and freeware that does as good if not better than some of the paid software. See for example WinSCP/FileZilla, VLC, Paint.NET CDBurnerXP, 7zip, Notepad++, foobar2000/winamp, etc.
on Android, many of the best (note: not "popular") apps are free or open source: Amaze, CalcTape, Fedilab, Metrodroid, OpenCamera, Ticmate.
The top paid app on Android right now is a $5 wrapper around a website (GoblinTools); In the top 10 are three watch faces, Torque (an OBD2 app), a PS4 remote play app, and a fancy notebook.
So, my take is that there's a higher density of good free apps on Android than paid.