I have a couple of theories: I think consumer preferences have pushed in that direction (e.g. I remember McDonalds chicken nuggets used to have chewy gristle in them), and JIT inventories mean that ingredients can be fresher, and food science (e.g. additives and preservatives) has improved, and improved flavor along with it, and there are also new preparation methods which improve quality of the final product.
Chickens have gained significant breast mass in the last few decades (so much so it causes "woody breast") and, with increased supply, the price of breast meat (less gristle) has come down proportionally. Like the McRib, economics drives McDonald's decisions.
Interesting. My impression has been the exact opposite of that. Ingredients seem more uniform, true, but they also are much less flavorful and seem to be higher in salt than ever.
So while that may be true, it’s absolutely true that they’ve changed.
I can go down the street to a restaurant called Left Bank and they have the most amazing brussels sprouts. I think they cook them in bacon grease. The outside is crispy and it has something like caramelized sugar on it. They are absolutely freaking delicious.
I don't really recall how my mom might have cooked broccoli and such, but I certainly identified things she did cooking that were not ideal as far as outcomes (and I would say she was a reasonably good cook).
I didn't like broccoli and cauliflower until I had them raw.
Of course, YMMV :)
What changed is the marketing around home cooking. Now everyone aspires to be their own private chef. It's understandable for people living in the mid-20th century western world to see all this as a bit pretentious.
The goal back then was just to get a decent healthy meal on the table. Any flourishes such as adding bacon, duck fat, or whatever else were likely seen as unhealthy, inaccessible, or just plain weird.
The spread of such information/science in recipes has increased from the slower era of cookbooks and newspaper columns.
prep it makes a huge difference and it's one of best tasting/healthy vegetable imo.