Whatever you buy now will be superceeded by something new and better in a year or two.
"future proofing" is not realistic for most pc products.
If you have a need now, buy now.
Today, I think ryzen 5600X is probably the best gaming processor you can buy(if you can find one for sale at the $299 MSRP)
the 12 threads and a very good IPC is all you need for gaming.
Few games can make effective use of 6 threads.
The 5900x with 24 threads will not likely do better.
Possibly if you play multiplayer with many participants would more threads be batter.
There is probably no graphics card that it would be a limiter.
One rule of thumb for a balanced gamer is to budget 2x the cost of the processor for the graphics card.
That would argue for a card like the 3070 0r 3080 if you can find one anywhere near the MSRP of $500, $700 respectively.
The higher your intended resolution, the more important the graphics becomes relative to the cpu.
You would want a 3080/3090 class card if you want fast action gaming at 4k resolution. Unfortunately, none are to be found at MSRP, indeed, none can hardly be found at all.
My suggestion is to buy what you need now, now.
Bust your budget for a great monitor, it will be with you for a very long time. Graphics is very easy to upgrade later if you need to.