I remember thinking a lot about action economy a lot when I first picked up 5e. Maybe that was because I had played 4e before that and I had trained myself to think in that action economy. Maybe not. Did 3e not have rules about non-combat actions in combat? I skipped that one.
These days, it just never comes up. We don't sweat it. If a player were to ask to do something absurd in one round, we'd say, "All that is going to use your Action this turn." And they would say, "Oh, yeah, you're probably right." If it's on the edge, maybe we'll allow it with some sort of Dex check. We've gotten away from thinking about it as an economy or a budget, and more into a loose consensus of what is possible. Bonus actions are different because they are all explicitly identified by the feature that provides them. We don't have to worry about classifying something into a Minor Action, a Major Action or a Free Action. It's either complex enough to take your action, or simple enough to just slip in.
