I'm following Rick Bayless' directions to check the _bottom_ of the avocado and use it or put it in the refrigerator (for 3-7 days) when it gives slightly.

https://www.rickbayless.com/ingredient/avocado-1/

I've mostly had good luck, but sometimes they're just bad to start with, bad because they're bruised from mishandling, or have been exposed to too much heat.

I don't see a lot of the tough leathery ones, but I have seen a few. (Seattle, so I'm not in the southwest.) I wonder if they are a different varietal or just dried out.