Hi,
Intel i5 4570 is not that bad, but is also not very good in performance.
Here see at
https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i5-4570+%40+3.20GHz
And way down at this list:
https://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Core+i5-4570+%40+3.20GHz&id=1896
It Will work with most of the games (at lower settings), however some games especially in multiplayer mode require a tremendous lot of CPU power.
Games like Crysis 3 , Far Cry 4, Far Cry Primal, GTA-V or Battlefield 3/4/Hardline is very demanding on CPU-power, just in single player mode at a reasonable game settings.
With that said it is totally ridiculous that a cpu has to be exercised.
That is a totally lie and has nothing with reality to do.
They are flat out lying or they don't now better.
It is simple not true!
And frankly, that is Not how an electronic device is working.
A descent graphics card to Your rig will do just fine together - I think.
but You will need a computer chassis that supports good cooling/ventilation and also a power-supply that can handle everything. Not to mention at least 8GB of ram - if You are running on a 64- bit operating system.
And the chassis has to be able to fit the graphics card in length.
Best regards, from Sweden