Millennials may have given rise to the hustle culture, but when it comes to putting in hours in the gig economy, Baby boomers might have them beat.

Baby boomers — those born between 1946 and 1964 — earned the most money, took on the most gigs and earned the highest ratings on Wonolo, a platform where companies can find short-term workers.

"I think traditionally, people think of the gig workers as millennials," said Beatrice Pang, vice president of strategy and finance at Wonolo. "We actually always knew that they are much broader. Our workers range from 18 years old to over 80 years old."

Steve Gregg, who at 51 is just a few years shy of being a boomer, came to gig work late in his working life after an injury put a halt to his career in horticulture. He said he saw it as a way to pay the bills while he bounced back.

"I didn't expect to fall in love with this, I really thought I would hate this work," he said.

But Gregg, who lives in Antioch, Calif., and also drives for Uber and Lyft, said he's "kind of fallen in love with the human race" over the course of some 14,000 rides in 2½ years. "I think that maturity, perspective, investment play a role in how you do this work, how you treat the customers," he said. "Years add to perspective, how much you're willing to invest."

Gig work gives older workers a way to earn additional income and can provide a flexible option between working full-time and total retirement, Pang said. But experts worry that a general lack of benefits, such as retirement accounts, sick paid leave or health insurance, could put workers at risk.

"It doesn't come with benefits for the future, it doesn't set people up to have a stable retirement and we need to think about policies that can address that," said Shelly Steward, a research manager with the Future of Work Initiative, part of the nonpartisan Aspen Institute.

Steward said it's hard to draw conclusions about the entire gig workforce from one company's data, but the number of workers in their 50s and 60s could be a red flag.

"There's also a broader question of why are people needing to do this in the first place," she said. "If you have a lot of people at retirement age who are pursuing gig work, it probably means that several years ago something wasn't quite in place to allow them to retire."

Whatever their reason for taking up gig work, boomers on Wonolo are outearning any other age group, with average monthly earnings in the Bay Area of $1,003 a month, according to that company's analysis of the users on its platform. Generation X workers, born between 1965 and 1980, earned an average of about $949 a month. Millennials, born between 1981 and 1996, earned about $777 a month, and Gen Z, the youngest generation in the workforce, earned about $616 a month.

Nationwide, about a third of boomers worked more than three gigs on Wonolo per week compared to 22% of millennials. Boomers and Gen Xers also tied with an average rating from the companies that hired them of 4.86 out of 5, slightly higher than millennials' 4.81 average.

"Boomers also do some of the most physical gigs," Pang said. "You would think that they're picking the administrative, customer service work that doesn't require the physical work, but they actually do a lot of physical work like fulfillment warehousing and general labor."