Try to lower some settings gradually and see how will that improve your frame rate.
Turn off as many background applications as you can, so that you can free up resources for Diablo 2 Resurrected.When it comes to optimisation on your side, here are a few things you could do. Players are reporting serious problems even on high-end PCs. With that being said, as we've mentioned above, even some gamers with the RTX 30XX GPUs and all the latest components are reporting serious problems with the performance, so it is not always just about what rig you have. That means that the first thing you need to check is if your system can handle the game and its minimum and recommended PC system requirements, and you will need to temper your expectations based on the system requirements.