You need to find out which of the PC games settings affect the VRAM the most, then dial back those. As this depends from game to game, its hard to give general advice that works the same for all games, besides universal settings like resolution and texture settings in example. As others mentioned, use FSR (or any other method) to play in lower resolution and upscale them to the output resolution you want. That means in example the game renders in let's say 720p internally and outputs to your monitors 1080p resolution. That will reduce the load of VRAM for the game, but still look okay for the output.

Older games (depend on how old we talk about) shouldn't have such a problem, because they were designed with lower VRAM in mind anyway. Emulation games hardly need more than 4gb VRAM.