The reason why this opening isn't played that often is that you give up a lot of space. Space advantage is one of several strategic key factors in a position. Kramnik once said about the king's indian that white has more space and that always means something, it's something you can work with. I think he would think so about the alekhine as well.
I played the alekhine for a while but I always suffered because of the lack of space. It's easier to go wrong with black than with white.
I encountered the alekhine once and I played the following line
Black should be able to defend but I think the positiion is easier to play for white. Also most Alekhine players prepare for the main lines with Nf3 so you have a high chance of catching them on the wrong foot.
White will try to attack on the kingside (Nf3, Qg4, Nc3-e4 or Nbd2-d4, Bg5, h4-h5 and so on).
Black will play on the queenside e.g. Na6-c5 or play c5 with the idea of c4
That Diagram is lines from the second video. There are four moves that black could possibly enact to go against this. As he states this is not a sound opening but who really cares.
The problem is that black's best moves are obvious, so there is little to hope here.
U can expect black go wrong (9...Qd7 was not obvious but even after 9...Nc6, black is fine, while the other moves where very easy to find), but why not playing something good instead?
If u want to gamble, why not playing poker and not chess?
Actually I do play poker! But anyways I was just giving out new information to those who might enjoy it. Those Videos are worth the watch. You don't play the Alekhine's defense for soundness, or at least I don't. I play it, for a surprise. It's fun. And also on move 10. (black's move) is incorrect. Yes black is winning but you have to play Qg4 to win a pawn. Especially in blitz this usually instantly wins a pawn because people move to fast and the knight can take on e4. Yes I'm aware that sounds very noobish, but never take the fun out of chess and be all analytical.