True, but it also doesn't mean they're not being exploited.
I choose to believe my employer cares about me, but it doesn't mean they do, and it's likely they might know I think that and use it to their advantage.
I hold nothing against personal faith, but I find it unsettling the balance of wealth across organised religions - seeing the gold opulence centralised at the (likely) expense of largely the poor across a lot of faiths is horrifying.
It might be more of a societal good for a local church to extract money from their congregation than for it to be spent on, say, padding Amazon's pockets, but it doesn't mean it's not taking advantage of said peoples.
Each to their own, but the notion that tithes might be linked to eternal glory or damnation for the giver can hardly make them entirely freely given.