Yes, that’s actually my understanding as well of pure mathematics. What I was trying to say is that in Stats (my field) and CS its quite common to go straight i

Yes, that’s actually my understanding as well of pure mathematics. What I was trying to say is that in Stats (my field) and CS its quite common to go straight into a TT job, and a postdoc is often a sign of particular prestige. In mathematics a postdoc is the standard post-Ph.D. route; of course some positions are very well regarded and others less so, but having a postdoc itself is just the status-quo for an aspiring academic at that point.