I think 28% of the population belongs in the lgbtq+ spectrum. a lot of older people were closeted, or actually unaware of their own sexuality. Younger people might just have an easier time coming out about it.
also, less and less young people are right leaning as the years go by, and the republican brand will be irredeemably tarnished for all future generations as the party of literal fascism, so get ready for even less of a share of future generations voting R.