[thraway180306]

It is in fact age limited precisely to combat ageism of the early 20th century. Otherwise only elders would get it (would they outlive the queue of their masters), when it's irrelevant to their career development (but beneficial to the prize's prestige). It was intentionally set up with this reasoning - not to be about lifetime contribution (which really compounds linearly in mathematics, there is no age dropoff "in the data" if you will) but making career easier for a very few young upstarts.

Otherwise it would be old people game.