Is it true that the performance of cemu is mostly determined by your cpu?

I am so sorry if this has been brought up but im noobish to this stuff and spent the better part of 2 hours researching to get some answers. I have heard multiple times now that the performance of games relies more on a good cpu than it does ones gpu since this is basically emulation. I found this a bit odd as I have previously read you need quite a beastly pc to run games such as BoTW. I admit I havent looked into things recently so this may have changed but can someone clarify? Which matters a CPU or GPU? Can a mediocre gpu be fine with a good cpu?

I have a i7 2600k, 16gb ram, and a GTX660 so im not sure if it would be worth it to dabble in CeMU atm. I would love to see how some texture packs and mods change some of the games I have (particularly MH3U)