I think the idea of "best play" is a myth.
Define best play
That's the thing. Sometimes, best play is objective, like if you have a mate or can win material without compromising your position. But sometimes it's subjective, especially in openings. It all depends what the player wants to accomplish, eg. king safety immediately, rapid development, central control, or a very quick and dangerous attack.
In modern chess, best play seems to mean making the move an engine suggests, but engines aren't perfect. Therefore, I think "best play" is a standard which humans implement on the game, sometimes without fully knowing what is actually "best play"
I am not going to read through all 150 plus comments to state an obvious conclusion. No chess engine has explored all the beyond astronomical series of possible games. So there is a possibility that one side has a series of combination that lead to a win and it could be either white or black, or given the best possible play on both sides all games lead to a draw, such as in the simpler Tic Tac Toe game. So in play an aggressive player might as well try for the win since it could be possible, but a wild move may result in a loss for them also. Evenly matched expert players may often find the game leads to a draw if they both play conservative. Since a full analysis of the game is impossible the only "evidence" is statistical, not a rigorous proof.
That's been said many times before. Not in the exact same words, but the same sentiment. Nobody knows if chess is a draw or not because humans aren't nearly good enough to know. And computers likely have hundreds of years of advancement before they come close to figuring it out. So yes, it is obvious.