It depends on who you’re calling young and which country you’re talking about. Millennials in the US will be the largest eligible voting block for the next 30 years at least, and maybe longer if they don’t have kids at a greater rate. Gen Z [edit: typo] is the smallest generation as a percentage of the total in US history so they’ll be out voted by older voters for the rest of their lives. In most other western/developed countries even the millennials are hopelessly outnumbered by older voters.