Red Dead Redemption 2 has not had a great PC launch so far. With launcher troubles to game-breaking performance issues, this port has been a bit of a mess for Rockstar. The game certainly looks better than it ever did on console, but hitting a consistent 60 FPS seems to take a pretty expensive PC rig.
For more info, check out this article on Polygon explaining the issues people are having: https://www.polygon.com/2019/11/7/20952369/red-dead-redemption-2-rdr2-pc-gameplay-freeze-crash
Also, check out this Bellular Gaming video for a deep dive into what's going on:
Image credit to Rockstar Games