Oof, yea I’d say looking at a dual channel kit of faster RAM would be worth your time, something like this 16 gb (8x2) PC3600/CL16 kit is just $50: https://www.amazon.com/dp/B07X8DVDZZ

Dual channel RAM will help with “CPU” bottlenecks, what type of RAM are we talking about (DDR4/5 and what speed?). What kind of storage are you using? Is resizable BAR enabled in the BIOS? High framerates but weird long pauses can also be storage related if you are doing all of this on a slow SATA SSD/spinning drive depending on where your drives are installed? I also agree with the poster who indicated watch out for bloaty programs that peg system resources at inopportune times.

A 12700 is only around 5-10% slower than a 13600k in games, and the 14600k is only an incremental bump from the 13th gen part. I’d question how big an upgrade ANY of the CPUs listed would be from the 12400, really depends on the workload and costs involved.