Hector Xu was on track for a career in academia when the pandemic upended his plans.

Tired of endless Zoom meetings and feeling cooped up in his Boston apartment, Mr. Xu decamped for New Hampshire, where he began taking lessons to fly helicopters. That led to a business idea, converting traditional helicopters into remotely piloted drones.

Mr. Xu’s company, Rotor Technologies, now has nearly 40 employees — including his former flying instructor — and about $1 million in revenue this year, a figure it expects to increase twentyfold next year. Gov. Chris Sununu was present for the first test flight of one of its drones.

“Covid hit, and it really changed my perspective,” Mr. Xu said. “You ended up spending most of your time in front of your computer rather than in the lab, rather than interacting with people, going to conferences. And I think it made me really yearn to do something that was more impactful in the real world.”

Mr. Xu, 30, is part of what may be one of the pandemic’s most unexpected economic legacies: an entrepreneurial boom. Stuck at home with time — and, in many cases, cash — to burn, Americans started businesses at the fastest rate in decades.

What happened next might be even less expected: Those businesses thrived, overcoming supply chain disruptions, labor shortages, rapid inflation and the highest interest rates in decades.