Some thoughts:
Cores do not count; it is the threads that count.
Some games actually specify 4 or more threads to run.
ryzen 3600 has 12, more than enough, I think for moat anything.
Past that is the question of how many threads can be usefully used.
I suggest to anyone who is interested in performance to buy a second monitor and use it for some displays such as task manager, cpu-Z and HWinfo to monitor what is happening while you are gaming.
You will always see all threads with some activity. Do not be deluded into thinking you need all of them.
(unless they are all at 100%)
What you see is windows spreading around the activity from a smaller number of threads.
You can perform an experiment by booting with a lesser number of threads to see how thread count impacts your performance.
Game developers want the largest possible audience for their games.
They have an incentive to keep game requirements low.
In any multithreaded system, there must be a master controlling thread.
Amdahl's law shows how the benefits of many threads is reduced:
https://en.wikipedia.org/wiki/Amdahl's_law
It points out the need for a fast master thread.
Today, so far as I can see, it is multiplayer games with many participants that benefit most from many threads.
Other games such as sims, mmo and strategy games depend on single thread performance.
Fast action games depend on a fast graphics card.
One reasonable rule of thumb is to budget about 2x the cost of the processor for the graphics card.
For the OP, a 3600 and a GTX1660 super is not far from 1:1.
That would suggest that a lesser cpu and a stronger graphics card might be a better balance.
While the new 10th gen intel processors need to be evaluated and sorted out, I think the i5-10600K is going to be the gamer's cpu of choice for anything less than top end builds.