There isn't a problem other than people's perceptions of what things should cost that they can't buy elsewhere.
It's pretty clear to me. The Radeon Pro 580 is a re-branded RX580. That card directly competes with nVidia's GTX 1060 6gb. That's an entry level card for 1080p gaming. Those cards are not designed for 1440p and 4k resolutions. For 700 bucks I wouldn't call that a bargain. Now if it had a Vega 56, or 64 that would be different, because those chips compete with the high end 1070/1080 cards, but fail to compete against Nvidia's flagship 1080ti.