Pawn Development?

Experts talk about developing your pieces all the time.  My question is: is there any value in the idea of developing your pawns?  Not talking about opening pawn moves.  I'm talking about when your pieces are out, and you don't see a move that provides any advantage, is, say b5, something you should consider a developmental move?

The answer is always... "in every position there is a best move."  I know that.  But "tactic" wise, is this a legitimate tactic?

Thanks.  So you could say, that in some positions, a wating move is the "best move" even though it doesn't forward an attacking plan (neccesarily).

If there's nothing else to do or you simply don't know what to do, it's a bad idea to move a pawn just to move it because unlike the other pieces pawns can't move backwards.  So each time you move one it permanently weakens squares on your side.... the up side is they gain space and attack new squares... but if you're moving pawns just to do something it's more likely to hurt you than help.

The term "development" is an opening idea.  In terms of middle game ideas pawns do play an important role.  Move like b5 can be very good and usually players are looking to facilitate their "pawn breaks."  A pawn break is advancing your pawn to attack an enemy pawn chain and break open a line for your pieces and is important in just about every opening.

In this french structure black's pawn breaks are at c5 and f6.  c5 is nearly always played, sometimes both c5 and f6 are both played.

In this caro / slav structure here black's pawn breaks are at e5 and c5.  If black can't play either during a game it will likely be very bad for him.