I tried my OLD pc with a GTX 1660ti and the CPU bottlenecked real hard only giving 60% GPU Usage at most
Not to sound* like an annoying snob, but please bare* with me here... Do you know what 60% GPU usage actually entails?
There's a plethora of elements that need to be taken into account when looking at GPU usage percentages. One, and I'd say the most important, the game you're testing. Each game loads a GPU differently; even more, each different setting combination loads it differently. Additionally, appended to the before statement, each
game engine loads CPUs (and GPUs) differently.
Don't pay too much attention to the GPU load and be a bit more holistic and look at raw FPS gain (including fluidity of frame delivery). If your FPS gain is like 2 FPS, that's when you consider a GPU upgrade can't be done before the CPU. If you have games that load the CPU first (like Civ), then the GPU may be upgraded after, but in most common scenarios the GPU needs upgrading first and foremost.
So, all that being said, I'll stand by my comment and just tell your friend to get the best GPU he can buy. If he gets a better GPU than you and gets
less FPS than you with your current PC, please let us know so we can include it in the Bottleneck chart thread.
Cheers!