>>96514399 (OP)
As porn brain-y and Skub as it may seem, I'm actually something of a supporter of the bimbofication of elves in kitchen sink games.
>1. It 'balances them.
Tolkienian Elves, being fantasy nobility, are fucking OP as a race concept. If they're going to be longer-lived, wiser, smarter and more beautiful, making them smaller, lither and more delicate is a fantastic, and fitting, drawback to the race. Otherwise you get something like DnD, where they kinda are Tolkein elves, but also kinda aren't in any respect, and that's hackish.
>2. It kinda makes sense in a multicultual society.
Every other race is typically much shorter lived, with physical and mental maturity reached by 20.
If Elves are physically matured by 20, but only considered mentally mature by 100, then you've arguably got something of a learning or developmental disability (if adult elves aren't hyper-wise genius').
Regardless however, a dynamic society changes its conventions and natures fast, and elves may not keep up as well given (proportionally in respect to their own existence) much less time to learn.
Hence, your modern, cosmopolitan elf, especially the adolescent ones under 100, may come across as airheaded, unaware or naive, and depend more on his or her looks and charms to get through new and unfamiliar social situations, as they are known for being especially beautiful.
This can actually make a good contrast between the more old-school isolationist Elves, who raise their children up in the old, classical ways away from shorter lived races, and the more urban elves who enjoy more social contacts, at the loss of social prestige as they come across as airheaded and over-dependent on looks.