I guess it comes down to whether or not you think the people who bought Skyrim four times are going to play Baldur's Gate or Starfield.
I think theme is a not inconsiderable aspect to take into account for RPGs, more so than most other genres, but I have to believe that to the layman Starfield will be as easy a transition as RDR2 was for GTA players.
The RPG nerds can be relied upon to play both, for the casual player, I guess it comes down to marketing, hype, and track record. I think those are all breaking for Starfield. But I don't have a great perspective
