alt Hacker NewsAs others point out, a song by the band, "The Who". But it's since come to be a phrase to suggest that the upcoming generation (the kids) are going to be okay.
As opposed to the more common refrain of "the kids these days…" (and then append some generational gripe like, "are just weed-smoking, lazy, game-playing, phone-staring, TikTok-headed, etc…"
Other than the TikTok-headed part, the phrase could easily be applied to at least as far back as the 80s (NES) depending on definition of game-playing. Before then, there was foosball and pinball. Nevermind the kids that play card/board games. Also, while not staring at a phone implying smart phone use, it was often said about teens having a phone growing out of the shoulder from them constantly being on the phone with friends.
So, yeah, kids these days...are just like the generations of kids before them.