Nina Kasman, an 18-year-old college student selling “ok boomer" stickers, socks, shirts, leggings, posters, water bottles, notebooks and greeting cards, said that while older generations have always looked down on younger kids or talked about things “back in their day,” she and other teens believe older people are actively hurting young people. “Everybody in Gen Z is affected by the choices of the boomers, that they made and are still making,” she said. “Those choices are hurting us and our future. Everyone in my generation can relate to that experience and we’re all really frustrated by it.”

“Gen Z is going to be the first generation to have a lower quality of life than the generation before them,” said Joshua Citarella, 32, a researcher who studies online communities. Teenagers today find themselves, he said, with “three major crises all coming to a head at the Gen Z moment.”

“Essentials are more expensive than ever before, we pay 50 percent of our income to rent, no one has health insurance,” said Mr. Citarella. “Previous generations have left Generation Z with the short end of the stick. You see this on both the left, right, up down and sideways.” Mr. Citarella added: “The merch is proof of how much the sentiment resonates with people.”

Rising inequality, unaffordable college tuition, political polarization exacerbated by the internet, and the climate crisis all fuel anti-boomer sentiment.

And so Ms. Kasman and other teenagers selling merch say that monetizing the boomer backlash is their own little form of protest against a system they feel is rigged. “The reason we make the ‘ok boomer’ merch is because there’s not a lot that I can personally do to reduce the price of college, for example, which was much cheaper for older generations who then made it more expensive,” Ms. Kasman said. “There’s not much I can personally do to restore the environment, which was harmed due to corporate greed of older generations. There’s not much I can personally do to undo political corruption, or fix Congress so it’s not mostly old white men boomers who don’t represent the majority of generations.”

Ms. Kasman said she plans to use proceeds to pay for college. So do others.

“I’ll definitely use the money for my student loans, paying my rent. Stuff that will help me survive,” said Everett Solares, 19, who is selling a slew of rainbow “ok boomer” products. “I hadn’t seen any gay stuff for ‘ok boomer,’ so I just chose every product that I could find in case anyone wanted it,” she said.