The last time I played the game (on Series X) I still had to rely on the uncap FPS mod for 60fps. It worked well enough but there were noticeable drops. Then they did the FPS boost BC patch, which I tried out, but it seemed to perform about the same.
Though not a native app update, I think this latest update did make the frame rate a lot smoother, especially considering I have 70-80 mods installed in all these cases. Most of the time to my untrained eye it stays solid enough. Also my TV is probably too small (43) to notice the resolution drops.
Also I think part of the reason they kept the dynamic res is because you can get graphics mods on Xbox, which you can’t on PS. It may be an old game but it’s still beholden to the old engine and getting a mod that adds grass and trees will still put more strain on it.
The PS5 version is probably perfect for people who haven’t played the game yet, but people who have would probably be better off playing on Xbox with all the mod options at their disposal. I mean unless you have a giant ass tv and the dynamic resolution bothers you that much.