I'm playing on a 3070 at 1024x768, and the frame rate fluctuates constantly between 25-40 fps. Is there any way to get a stable 60 fps? I'd even settle for a stable 30 fps.

no framerate wasn't the thing back then and honestly for many of us it still isn't... you could build a sand box to run the game inside and Windows 11 -12 may make that something people need but it would still just run at whatever framerate the system can handle not a set number