You're kind of proving my point. Why buy a 5600 now to upgrade to a 58003d later when you can just get the 58003d now and save money and trouble? Or even better a more recent equivalent CPU that isn't already a dead upgrade path. I'm not talking about cutting edge here, just something not terrible like most "entry" level GPUs these days.
Edit: Argument aside,a 5600 is fine as far as CPUs go, at least for now, but I've seen people recommending a 3600 to match console prices. Just no.
These old cards are not always easy to find at a good price, or at all. While the raster performance is still fine, you have little to no RT performance to speak of and you'll have to live with FSR2 for years to come. If someone bought it at release it'd be fine, but I would never recommend one in 2024. Just another part you'll have to swap very soon.