Yeah, frozen is pretty good and quite often better nutritionally as it is more ripe than the "fresh" stuff since it doesn't have to be cosmetically appealing or to stay "fresh" while going on the trip through the cold chain.

The general problem is with "fresh" as it is specifically optimized for the time spent in the cold chain. Produce has less water as that would bruise. Stuff is picked while unripe and then "ripened" in warehouses. Characteristics that cause degradation are bred out (like the enzymes in roses that give you the scent that is the defining characteristic of a goddamn rose). etc.

And, you are quite correct that the overarching problem is the consolidation of the food chain into a small number of giant "agribusiness" entities.

Yes exactly - and more broadly pretty much all food consumed globally is automatically selected by tolerance of storage + packaging + shipping. Many varietals and whole specimens have been lost to the annals of history because they cannot make it to a Walmart in North America from Mato Grosso in a scalable (and profitable) way.

Bananas, for example, are practically a miracle fruit for scalable production and distribution. They are incredibly consistent - have resilient skins, have lots of structure that prevents damage from packing, come in easily managed bunches, and (if temperature controlled) the ripening process can begin on demand at point of delivery.