If you have a 1080p monitor you could see FPS gains of 10 or more (depending on the game) and it would be worth it if you have a high refresh rate monitor (144Hz or higher). But a 5700XT is a 1440p gaming card so if you have a 1440p monitor than upgrading to a 5600X wouldn't give you that much of a boost in frames. Granted it'll still get you about 10 extra FPS avg but most of the work at 1440p or higher is thrown at the GPU. Only at 1080p is the CPU given a lot of work to handle during gaming.
Conclusion: if you're gaming at 1080p, then yes it's not a bad upgrade and can be worth it - but in my opinion a 3600X is still fine since it's relatively new. It'd make more sense if you were upgrading from a 1000 or 2000 series Ryzen CPU. But...