...to stop assuming that there are invisible things. :)
What I mean is that, with all of the information we have at our disposal, there's no reason we can't get a lot closer to explaining what happened on the field that caused the Yankees to lose 11 more games than the numbers say they should have. We'll probably never find all of it...but we can micro-analyze each game of the 2017 season and figure out what determined the difference between winning and losing and also figure out which team should have won or lost based on bases gained/lost and look for patterns for each team and for all teams together.
I refuse to believe there aren't any.
Of course, until we do that, my stopgap answer is to rate MVP by what did happen (and rate historical player greatness similarly by what did happen) and to rate player future projections by what should have happened.
It seems like a reasonable compromise to me.