I applied for postdocs this past year but didn't get any offers. Unfortunately it's not possible for me to get any feedback on what went wrong. One of my letter writers said that I am not doing anything "wrong," but the competition for any academic position is "extremely brutal." He also said that academia isn't really a meritocracy and that there's a lot of randomness in the hiring process. He also said that there's an element of "social engineering" in academic hiring that's intensified in the past five years and that I shouldn't take it as a sign of my mathematical ability.
I think he was trying to make me feel better but I still feel like a loser. I wish I knew what was different about the candidates who did get hired. What made them different from the candidates who did not get hired?
Is that the end of my academic career? What should I do in the meantime before trying again? How many times can I try?