I mean, you actually probably COULD play Dark Souls on it, but you'd be turning settings down a bit I bet (I don't actually know how optimized that game is). I'm pushing a 1440p display which certainly doesn't make things easier on the Mac.
The biggest annoyance I've hit actually is that game controller support is pretty bad. Don't expect generic USB HID game controllers to work, support for that isn't baked into MacOS the way it is Windows (Via DirectInput, etc).
The happy path is pretty much specifically a bluetooth xbox controlle.
(Dark Souls is my favourite game/series…how did you know)