I mean, yeah, the mission design is very restrictive, but I don't think this is necessarily dated, it's just a different approach. I love emergent gameplay and different ways of doing missions, I mean, BotW and MGSV are among my favorite games ever, but there's something refreshing (to me) in Rockstar's approach. The curated aspect of missions in RS games mean they can be as bombastic and narratively exciting as a linear game like Uncharted, for instance. Do people complain that Uncharted's missions are restrictive? No, because it's not an open world game, therefore freedom is not the focus. Well, with Rockstar games freedom is only the focus when you are free roaming, but inside the missions the focus is on the events the story is trying to tell, and I think RDR2 does that incredibly well.
It would be one thing if the missions were boring and predictable, but they are not. You never quite know what is going to happen. It's not an unpredictability driven by freedom and mechanics, but driven by the narrative. With Rockstar games you can get both: one in the free roaming and the other in the main missions. I don't think that's dated, it's simply trying to give the gamer the best of both worlds.