I feel like this thread is going really be “available in your part of the US.”
Grocery stores and populations are pretty varied across the US. What you can easily get in a San Francisco, Manhattan, or Boise grocery store can differ quite a bit.
Sure but there's also tons of produce that has a low shelf life or doesn't travel well (e.g. bruises easily) so you don't find it anywhere except right where it's grown.
e.g. I live where Pawpaws grow. I've never even found a whole one because they perish so fast.
My best advice would be once they start falling on their own try shaking them out of the tree. But don’t try shaking too hard because it’s completely possible to shake unripe ones out too…
The original intent was to learn about fruits and veggies that most americans would be unaware of or dont have access to eg. brazilian grapes, ube, drumstick, adzuki beans etc. but good point.