That really seems to favor black by a rather large margin. Wonder if there are any stats on the win ratios for each color in this format. And how do they decide who get's each color?
Whenever you try to force an outcome in a sport, you get further and further away from the original game.
https://slate.com/culture/2009/01/why-the-nfl-should-replace...
I think given the probabilities in the 538 model Carlsen's decision makes a lot of sense. Why slug it out to a probable draw with the chance to lose out of nowhere when you can move to another format that drastically favors you?
[1] https://fivethirtyeight.com/features/carlsens-bizarre-decisi...
Blitz is almost an entirely different game from classical chance. Yes, technically the rules are the same, but tactical ability and ability to think under pressure plays a massively more important role than positional ability, which tends to be the deciding factor in top level classical chess.
A 5m to 4m time advantage is the equivalent of a 100-200 point handicap. Think about it... if both players are evenly matched for 30 moves taking the same amount of time, say 3m, then you end up with an interesting middlegame position where White has 2m and Black has 1m. Now you are playing bullet chess with a 2 to 1 time advantage, which is more of like a 300-400 point handicap.
All that to say - blitz chess, even at the world championship level, is characterized not by "slight inaccuracies" but by major mistakes if not outright blunders. You can even have wild swings in the final minute as each player makes critical mistakes.
To get a feel for chess at this speed, I highly recommend watching some bullet chess streaming videos from chess.com or lichess. It is both highly entertaining and very instructive about the time aspect of chess.