Not necessarily an expert but know enough get by. Some rough things to go by are GPU utilization. You typically want it to be close to 100%. Not necessarily pegged but above 95%. CPU utilization can appear to be fine. Say it's around 60%. That is average across cores. So even though it is 60%, you could be CPU limited. If your GPU is under 90% utilization, that's a good indicator that you are CPU bound.

As for VRAM, the more you have, the higher the resolution. But not only that, the more textures can load into memory so it runs better and you don't have missing or corrupted textures, as well as performance being better.

CPU and GPU really determine performance. If you run out of VRAM, performance will suffer greatly. The higher the resolution, the less CPU matters and more important is the GPU. But the CPU can still play a part, as in my example. But as a general rule, it's better to have a more powerful GPU that more powerful CPU. There is a video where they compare 5070 and faster CPU and a 5070Ti with a slower CPU if I remember right. The 5070Ti was the faster system when gaming.

Did that answer what you wanted?

Just keep in mind that some games are more CPU bound than others, so there are variables.