Younger workers embraced the idea of a personal brand as a way to get ahead, and carve out some power and security in their careers. But posting through it has its drawbacks.

Kahlil Greene’s father works as an accountant and his mother does something involving “administration,” though he doesn’t know the details. His parents rarely spoke about the goings-on of the office when he was growing up. His mother sat in a cubicle farm — he remembers this from “take your child to work day” — and then she or his father picked him up from the Boys & Girls Club and they talked about other topics, like “Judge Judy” or Serena Williams. Their work never bled into their personal lives.

That made it tricky for Mr. Greene, 22, to explain to his family why he had turned down a job offer from McKinsey to build his online brand as “the Gen Z historian.” He has drawn over 500,000 followers on TikTok, LinkedIn and Instagram to his posts about history and politics; his money comes from brand deals and public speaking. To Mr. Greene, it seems natural for his source of income to be something all consuming, something he thinks about while falling asleep and talks about nonstop with friends.

“There’s no clear delineation between my work life and my personal life,” he said. “Sometimes it can be exhausting.”

Mr. Greene, in other words, finds his job and self inextricable. Like many other millennial and Gen Z workers, he is his brand. This can feel freeing. It can also feel grueling.