Have you watching benchmark videos to see how far behind your 2600 is? A 13100 would give you 100% more speed, much less the 14100 that is coming out.
Since you focus on games with the 165Hz, buy a 7600x, get a quality motherboard like an Aorus Elite AX or MSI at that price, 32GB DDR5, then in 3 or 4 years you buy a 9950x and go to 16 cores on that motherboard to do a system upgrade.
Trying a new system is not the same as using it for a week with all of your programs installed and you see how responsive it is with your programd open and running.
You are missing a lot of instruction sets, and buyig AM5 now or next year buying Intel with feed the 165Hz a lot smoother and you will make better use of it. The 2600 can't keep up with the 6850 and provice consistant smooth frame timings.
You need to build a new computer including new power supply. You can only re-use the Radeon and storage in new system, everything else must be replaced. Check the price of 2600K on eBay. You whole PC minus 6850 might sell for $200. I would argue that you're holding on to something that can't sell anymore.
Is Capcom a publicly traded company? There's your explanation.