you are shopping in the wrong places.
and you need to build a relationship with a good local fruteria.
ours will pick the best fruits for us, and sometimes tell us not to buy something that day.
skip big grocery stores like Disco. and most chinos.
Buy from a small fruit and vegetable stand. In my neighborhood, within 5 blocks, there are at least 20. 2 of them are really good, 5 or so are miserable, and a bunch are average. They go every morning to the wholesale market, and the good ones actually pick good fruits and vegetables.
Like any other trade, there are people who care, and there are clockpunchers.
We have been getting great berries- blueberries are basically over for the year, I freeze em. Strawberries and cherries and grapes can be excellent. Really good melons this year, we go thru one or two a week. I have had great apples, and mushy ones. We have been digging the little brown tomatos this year, they are really tasty. Its all out there, you just have to look.
Also, there are farmers markets with direct from the farm produce- El Galpon, on Federcio La Croze, Mercado Bonpland on Bonpland in Hollywood, and more. They usually have very high quality, seasonal stuff that is fresh and good.
The Agronomia market is only once a month- but its great.
https://www.facebook.com/Feriadelproductoralconsumidorenlafauba/
And its cheap- we buy huge bags of fresh organic stuff there, usually more than we can eat.
I have noticed a big improvement in the variety, and quality, of produce available during the last ten years- there are more and more organic farmers who really care. Kale used to be totally unheard of, now its common. Neighborhood matters, of course- if you live in a Villa, they arent going to have ricula. Higher income neighborhoods have better produce and selections, because it sells.