To clarify: Why would a plant/bush/tree evolve to produce a large fruit or something similar where there are easier, more effective ways of reproduction?

I know that berries have seeds and when eaten by animals and shit out elsewhere, will grow new plants, but why would a plant take so much from itself to produce fruit instead of say, pollen or something like the oak seeds?

This isn't supposed to be a banana argument to try and prove the existence of God or anything, but I'm just curious to see what people have to say.