The lead intel has for gaming is around 3%~15% as long as you keep the resolution low (1080p) and the details at medium or high (depending on the game), and those numbers are mainly if you pair those CPUs with a high end RTX 2080TI, so if thats your case scenario go Intel.
Ive seen and read about 10 reviews of the new 10th gen Intel chips, from Tomshardware, LTT, Guru3D, GamerNexus, Hardware Unboxed, Paul's Hardware, Teach Deals, etc. and what i got from those is:
- If you only care about high FPS, 1080p, medium details and money is a no-problema then i9 10900K
- If you care about FPS but money is an issue then 10600K. (Gamer Nexus has a guide on how to turn a Core i5 10600K on an almost 10900K with just a few BIOS tweaks).
(The above two if you can find stock at all).
3. Everything else -> Ryzen 5 3600 / 7 3700X / 9 3900X + B550/X570 motherboard.
If you can wait to build a system then you shoud wait for new restock since after human malware started there are lots of missing components.
Keep in mind that the new 10th gen will require a Z490 board and a very decent cooler for stock operation. If you plan to enable MCE or OC, then the very decent cooler transform into a 360mm AIO as the minimum and you will have to factor a power consumption of around 200~320 Watts for the CPU and Mobo alone (depending on the 10th gen model).
Heck now that I think about it maybe the i9 9900K is the best bet (albeit been a dead platform) right now for really high FPS, maybe not the highest one anymore but still, Who can see the diference between AVG of 220 or 225?
As someone said already theres no wrong buy right now, unless of course you buy the i7 9700K or the i7 10700K, those two seems to be a really stupid buy.