A pawn majority is strategically valuable because it provides the potential to create a passed pawn. By advancing the majority pawns systematically, one pawn will eventually advance past all opposing pawns and become a passed pawn that threatens to promote.
Not all pawn majorities are created equal. A "healthy" majority (with no doubled or isolated pawns) can readily produce a passed pawn, while a "crippled" majority (with structural defects like doubled pawns) may struggle to advance effectively. A 3-vs-2 majority with healthy pawns is generally more useful than a 4-vs-3 majority that includes doubled pawns.
In practice, queenside pawn majorities are often considered more valuable than kingside majorities because the kings are typically castled on the kingside. A queenside majority can create a distant passed pawn that diverts the opponent's king, while a kingside majority might weaken the king's position if advanced. Understanding when and how to mobilize your pawn majority is a core endgame skill.