For me, anything 25 FPS or higher is 100% fine and I’ll be enjoying my time. I never play competitive online shooter games ever, though. All single player ones like GOW and the likes. I game on a 60 Hz 4k monitor. GPU is AMD RX 6600 alongside Ryzen 7 5700G and 32GB RAM. My games are set to meduim most of the time at 4k. Demanding titles are on low. Surprisingly, GOW and GOW Ragnarok are both set to ultra and I still get around 40ish FPS.
I don’t really obsess about framerates myself and I’ve never had the kind of budget to have the latest and greatest parts but from what I’ve seen, somewhere around 30fps is fine.
And even though you didn’t ask, the last setting that I ever sacrifice is draw distance. I’ll turn down textures and shadows and reflections and everything else before I sacrifice draw distance. I don’t need realistic graphics to be able to immerse myself and have a good time. But things popping in and out of existence in front of your eyes are the ultimate immersion breaker for me.