If you want younger people in office at the national level, you need to be supporting younger people at the local level. It's not a 100% pipeline, but that's a huge part of the current. And it's not just about voting for them, you need to be out there actively canvassing, campaigning, donating, and continuing that support after they get elected, if they get elected.

One problem: Younger people in many parts of the country literally cannot afford to or aren't able to make it work out. You end up with a lot of retired people in those elected positions because they have the time to run a campaign and then do the job, and the non-livable wages that these positions pay out (if they pay out at all) are just icing on the retirement income cake. But even candidates that aren't retired often have to put special effort into appealing to the retiree crowd, because those are the folks who have the most time to help support the campaign and/or money to donate.

Another issue: Young voters are, super generally speaking, not reliable voters especially when it comes to mid-terms and primaries. You can say they don't vote and don't help out with campaigns because nobody/the party doesn't appeal to them, but it's a chicken and egg issue.

Anecdotally speaking for my general area, the younger folks who run often seem to lack appeal to older folks (who do vote), have a hard time communicating their platform, and/or their platform has little to do with the position they are running for. Simply speaking, they aren't electable, either.

You can argue the older folks also aren't electable, but that doesn't change the truth. Somebody running for town council with a platform to vaguely support Palestine and regulate AI comes across as out of touch with local politics and what they could reasonably achieve compared to the older folks who want to stick to milquetoast agenda items such as to approve funding for new classrooms and expand pedestrian walkways on main street.