Young people aren’t voting = political parties seeing no reason to appeal to them.
Older generations vote, so politicians who appeal to older generations get promoted over ones who might otherwise have broad appeal.
And that works great until the old farts start dying and the young people the party spent so long alienating don’t trust them for some fucking reason.
So the fun thing is that you get older every year. So does everyone around you. What seems to actually happen is that as younger voters age they realize that they should actually vote* – in 2000 32% of the 18-24 bracket voted. By 2020 those people are at the upper end of the 25-44 bracket [the census has wonky ranges], and 55% of them voted.
This trend has been going on back as far as there is data. There is no ‘until’.
And if those numbers seem really low to you - yeah they are. For comparison about 70% of people 64+ have voted every presidential election year, back to like the 80s. And it’s even worse for midterm years! In 2022 people 64+ voted at about a 2.5:1 rate to people under 25.
*in fairness there’s also the factor that as people age they tend to have more stable lives, more ability to take time off, etc. And there are states that DO make voting hard on purpose (notably all governed by the same party). Reasons why supporting early voting, mail in, mandatory time off, etc. Are all also very important. But in much of the US it’s not particularly difficult and people still don’t do it.