Eggs from healthy chickens with good diets have more nutritional value and taste better than inbred, locked-in-a-tiny-cage, fed-only-corn, factory-farmed eggs. Visit a rural area and try some eggs from a chicken that's allowed to run around and scratch and eat bugs and seeds, it's not even comparable to thin-shelled pale-yellow-yolked garbage in the grocery store.

Anecdotally I think food tastes way better in general today than it did in the 80s or 90s. Avocados used to be hard and almost flavorless, strawberries were watery and less sweet, restaurants are making much more interesting and complex dishes than I remember ever seeing as a kid, and food in general even just looks better. Go back and watch some old movies with some "fancy" dinners, everything just looks disgusting, like it was all cooked in a microwave or something. The situation looks like it was even worse in the 60s and 70s.

but produce really has gotten blander. I've never been a fan of regular Roma tomatoes, and even grocery store heirloom tomatoes mostly just taste sour. but I recently had the opportunity to eat a pizza with heirloom tomatoes from a friend's garden, and it tasted like the second coming of Jesus Christ in my mouth. like, not exaggerating, I was briefly moved to tears by how flavorful it was.

Presumably they are referring to the reduction in average quality that came with scale and cost related changes in food production. If you buy (expensive) eggs from a small farm, they objectively taste better than eggs from a cheap or even average grocery store. My impression is that whatever “innovations” produce this difference had not yet been put in place 50 years ago.