Because motivation is a lie

I got that impression from this part of your comment

that’s where the collection plate likely originates from.

The idea of donating in church or donating to a spiritual leader is waaaaaaaay older and recorded

Christian religions flow the teachings of Jesus who followed/was aware of/modified the teachings of Judaism, which already had centuries of tithing already established. Dude didn’t invent it.

Tithing is in the old testament. It’s from a long time before Señor Christ.