Olives are landscape tree in Phoenix Arizona and no one (well very few people) eat the olives.

When the olives ripen and fall, it creates a big mushy mess all over the yard and sidewalks, so there are services that go around and spray olive trees with a growth regulator to prevent fruiting.

I always felt the whole thing was a bit wasteful and they should have been turned into oil but I suppose harvest isn't practical at scale.