For those that don't understand how the MVP system works in Marvel Rivals, let me try to explain it clearly-
Basically, if you're playing a character like White Fox, the MVP system compares your performance in that match to the performance of other White Foxes. If the average White Fox gets 15k healing in a 10 minute match but you got 25k, your chances of getting MVP are high. It also takes into account your performance in that match as the MVP system is doing that for each character on your team. Whichever person performed the best average-wise as well as on the team(or at least almost the best on the team) will get MVP.
This is also why new characters are basically MVP merchants. People are figuring out the character and performing poorly. Because of this, anyone with half a brain that performs even mildly well on that new character is so far above the "average performance" that they're almost guaranteed MVP. As time goes on, the average actually settles in to what it should be and they become a normal part of the MVP system where you actually need to perform well to get MVP.
Hopefully this helps! This is just my understanding of the system so I could be missing some parts.