A CPU bottleneck rarely shows up as low average FPS. It shows up as stutter, weak one percent lows, and a frame rate that will not climb no matter how strong your graphics card is.
If the check flags your CPU as the weak point, do not buy a chip yet. Confirm your motherboard socket and RAM type first, then compare processors, because a CPU upgrade often drags the whole platform with it.
Do not buy on a guess. Check your exact setup in 60 seconds and see the one part that matters.
predicted:FrameReady Can I Run tool. FrameReady uses predicted PC targets until official PC requirements or measured benchmarks are available.
official:Rockstar Games GTA VI page. Rockstar lists GTA VI for PlayStation 5 and Xbox Series X|S. FrameReady does not treat PC requirements as official until a PC source exists.