Purpose of saving pawns

Suppose black and white pieces were there in middlegame. In both positions, the pawn is very important since it helps in protecting a minor piece. This minor piece is important because because it controls many squares in the opponent side. Without the pawn, the minor piece will just be in danger.

Also, they act as bollards at times, restricting access to files, squares, etc. Often visualising the effect a seemingly harmless pawn will have on a position in 3 to 5 future moves can mean everything. Naughty little minions. So tricky...
"The winning of a pawn among good players of even strength
often means the winning of the game." - Capablanca
"A pawn is a pawn" - Fischer