IMO the minimum viable CPU upgrade for that platform going forward is a 5700 or 5800X3D. Gone are the days 4 cores are enough for modern games. I have a 5800X3D and it is often taxed to its limits, 50%+ utilization but still provides 160+ fps at 1440p. At 4k It will be useful for years to come.
As others have said as well, you need a better PSU for a better GPU. An 850w Seasonic focus gold or better, Corsair RMe / RMX or better would be my opinion on the PSU.
I disagree. A 5800X3D is very capable even today, and will be for at least a few years. He does not need new RAM, but that would be a very cheap upgrade at some point later. Even the cheapest AM5 build would be 400 dollars when you could just spend half of that on a CPU to get you 85% the way to AM5 performance.