That's the perpetual debate, PC or Console?
First off, am I assuming you're talking about a 1920x1080 resolution monitor, either with a 60Hz refresh rate, or with FreeSync?
I'm going to assume that, given that you're looking into an RX 580.
I'm a PC owner, and don't really use consoles. But, the general summary is:
- PCs aren't just gaming/entertainment units, they can do more things (office work, web browsing, and numerous other things that don't fall under gaming/videos
- PCs are more expensive, but, due to things like Steam sales, etc., games tend to be cheaper
So, you could say that the PC has more costs front-loaded, but in the long-run saves you, and can potentially be upgraded without having to get a whole new system in the future (whether this is feasible over a period of time that would be the lifetime of one console generation is harder to say)
HOWEVER - from what I've read (NOT personal experience), while consoles target a resolution/refresh rate, they don't necessarily deliver that all the time. I remember debates about the "limits" of an RX 580 for 60fps @ 1080p, but then seeing the argument countered that consoles don't consistently deliver that, plus, PC users have the option of going full on high details, or backing them down, whereas consoles do not (again, for me, secondhand info) have the details cranked up as high as can be done on a PC, if your video card is capable.
I'd say in the long term, the PC is the way to go, especially if you need to do other non-gaming related things. For strictly gaming, the answer might not be so clear, but long term, I'd probably still give the edge to the PC.
If you do go PC, though, keep an eye on the falling prices of the RX570/RX580/RX590 (the Polaris cards). Potentially in January, when the RX 5600 XT comes out, it could exert further downward pressure on the Polaris cards, as well as the newly released RX 5500 XT.
I would say if you're going to go PC, though, it might be best to consider the RX590, or possibly the GTX 1650 Super (performs about RX 580 range), 1660 non-Super, or 1660 Super. The latter two might be overkill, though the 1660 non-super should probably be a non-starter, since the 1660 Super is generally only $10 or so more.