I have bubbled a tournament numerous times.
Usually it's a case of having the best hand pre-flop (AA, KK, and less often AK) and voluntarily getting it all in to unfortunately be called by worse which ends up winning.
Less often I've been trying to hold on to min cash with a micro stack but blinds and antes force you in when the "piggybank" is empty. In these cases, I also sometimes have the best hand pre and lose to a worse holding or more often having complete garbage which doesn't get lucky.
I'm only ever folding premiums when the min cash is really important to me, for example, when my
bankroll is decimated and a min cash is the way to start to build anew.