Consonants.
J names always tend to be popular.
Currently girls seem to have names that are vowel-heavy with only a few consonants, and usually the same ones - L, V, N, M and maybe a T or R, so they seem samey.
Starting with L - Lily, Lila, Lola, Luna, Lyra, Lilia, Liliana
Starting with M - May, Mae, Maia, Maya...
V - Eve, Evie, Ivy, Eva, Ava, Evelyn, Violet, Vivienne, Genevieve....
El- Eleanor, Ellie, Eloise, Elena, Helena, Eliza, Elise, Elizabeth...
A names - Amelie, Amelia, Aurelia, Aurora,
TH names are currently very popular. Theo and Thea etc
R names - so many boy's names starting with R. I can picture a school class with Roman (x 3), Rupert, Reuben x 4 (but one will be Rueben and one will be Ruben), Rory, Rowan, Rohan, Ruan, Rufus...