I alwayse check this before downloading apps because i dont want apps to spy on me. And what i noticed in practise is that usualy payd apps offten dont collect any data and even if they do its less data than free apps.
So obviusly they collect that data to sell it and to make money that way. And if you think only big companies for advertising buy that data you are wrong.
Gowermants, secret organizacions and milioners who want to control your life is bying that data the most.
Sure, Graphene OS tries it’s best to limit Apps, but if you don’t trust an App, you just shouldn’t run it, no matter the OS.