Check the ingredients... a lot of them are heavily adulterated. Not to say they aren't tasty, but they aren't even necessarily "avocado".

I'm sure they have a step where they add an oxidation prevention molecule- I bet there's some ligand that binds to the oxidation enzyme in avocados. Or maybe high pressure? https://www.hiperbaric.com/en/the-impact-of-hpp-technology-i...

And almost all of them are too sour (imo), probably from the antioxidant.

Maybe like for other fruits ? They take them still green.