Air carrier First Officer reported a conflict with traffic ahead of them during final approach. Flight crew executed a go around due to the other aircraft not exiting the runway.

Narrative

The event started with a visual approach to 8R. While we were between LASSY and DEPLOY; another plane was vectored in front of us and they overshot the final approach course. As soon as we saw how close it was to us we started slowing down. Approach started vectoring us off the final approach course and giving us speeds as the distance between us closed to within 2 NM (per TCAS display overlay on my Nav display). They were about 2000' below us so there was no RA. Eventually we both ended up back on the approach and we managed to get about 2.5 miles between us by the time they touched down. The other plane was unable to exit Taxiway NK due to another plane being stopped on it. They appeared to be slowly proceeding towards Taxiway NN instead. We were at about 200' AGL when we concluded they were not going to clear the runway before we would touch down and a go-around was executed. During the go-around; ATC asked us more than once what the reason was for the go-around. At one point; it seemed they were more concerned that we had received LAHSO of NP (which we had received but it would not have changed the cause or effect of the go-around). I'm unsure what kind of plane was in front of us that caused us to go around; but the plane that was stuck on NK looked like an Aircraft Y.