Commercial orchards are full of carefully pruned and closely spaced trees of known varieties and the margin is still not great on fruit production. It simply isn't a good way to make money to drive all around town picking unknown variety fruits with pest blemishes from irregular trees and then try to sell them. This is why maps like Falling Fruit have been around for years and yet if you walk around Berkeley (for example) you will still see plenty of fruit on trees.
better systematically harvested and sold than fallen to the ground and rotted
Animals will eat those or the composting of the food simply returns nutrients to the environment
i don't want the rats in my neighborhood to return those nutrients to the environment, and i don't like tracking composting fruit into my apartment, though i guess if parrots eat the fruits while they're still on the tree that's okay
Even better when done without profit as a motive, like community volunteer efforts such as https://www.portlandfruit.org/
that's better if it works better, but often profit is what works better as a motive. ultimately what matters is that the fruit finds its way to hungry mouths—and that those mouths are human mouths and not rat mouths!
systematic harvesting is much better at that; whatever kind of point-scoring exercise people engage in on the way is irrelevant
Yeah in my experience most people don't like giving up the location of public apple trees etc. so they can harvest them themselves anyway.