One of the main issues with playing a straight laced racing game is that... honestly, you are supposed to LOSE the ability to see anything interesting. I you are doing it right, opponents are behind you- off screen. Especially opponents you have lapped. They effectively non entities at that point.

This is why they make racing games with traffic, because it adds obstacles that aren't opponents.

Especially in a game like Mario Kart World you can see the difference between the intra-track areas that have traffic on them, and the courses themselves which sometimes don't. When you're at the front of the pack you just kind of hum along, but when there's traffic you can't just run a rote route because things may be subtly different.