I know breast milk changes with baby’s age. Why then is it not “bad” to feed a baby breast milk that was pumped from a different age ?

For example, if my baby is 6 months old now and I’m feeding him breastmilk from my freezer stash that was pumped when he was 1 or 2 months old, wouldn’t that be the wrong makeup of things he needs?

Just curious - couldn’t find anything online about it and wondering if I should cycle my frozen milk in more often instead of letting a freezer stash build and giving fresher milk.