Moin, I will soon get a RX 570 4 GB Strix, and currently have an i3 3220 and 8 GB DDR3. Power supply is a Pure Power 10 400 watts. I will probably upgrade later to a Ryzen 5, but the money is not enough. So now my question: is the RX 570 of the i3 3220 very gebottlenecked, or just something? That would not bother me so much then. I play CSGO, Fortnite, PUBG, and Rainbow six wins.
In places, the old I3 will slow down, yes
Seeing that you charge the graphics card with lots of details in the games then the CPU does not slow down and your card can play its full potential.
For now the combination is sufficient. The graphics card is required of most games anyway more.
Is it worth it to upgrade to an i5-2500k?
That would be + 52% performance. If you find a good offer then why not