arguments for both but botvinnik has beaten Alekhine before in 1938 and they both probably weren't in prime. This is the game
Botvinnik probably improved since this game and Alekhine probably was exiting his prime. It's unclear who would've won but i'd put my money on Botvinnik.
I found this:
https://www.chess.com/blog/Spektrowski/on-the-hypothetical-botvinnikalekhine-match
while trying to answer the question: "If Alekhine had played Botvinik in 1946 who would have won?"
Don't read it. It's horse manure. Instead please answer my question and give some BRIEF reasons.
Thanks.