(NYTIMES) – Mr David Gross, a New York-based advertising agency executive, convened the troops over Zoom this month to deliver a message he and his fellow partners were eager to share: It was time to think about coming back to the office.

Mr Gross, 40, wasn’t sure how employees, many in their 20s and early 30s, would take it. The initial response – dead silence – wasn’t encouraging. Then one young man signalled he had a question. “Is the policy mandatory?” he asked.

Yes, it is mandatory, for three days a week, he was told.

Thus began a tricky conversation at Anchor Worldwide, Mr Gross’ firm, that is being replicated at businesses big and small all over the world.

While workers of all ages have become accustomed to dialling in and skipping the wearying commute, younger ones have grown especially attached to the new way of doing business.

And in many cases, the decision to return pits older managers who view working in the office as the natural order of things against younger employees who have come to see operating remotely as completely normal in the 16 months since the coronavirus pandemic hit. Some new hires have never gone into their employers’ workplace at all.

“Frankly, they don’t know what they’re missing, because we have a strong culture,” Mr Gross said. “Creative development and production require face-to-face collaboration. It’s hard to have a brainstorm on a Zoom call.”

Some industries, like banking and finance, are taking a harder line and insisting that workers young and old return. The chief executives of Wall Street giants like Morgan Stanley, Goldman Sachs and JPMorgan Chase have signalled they expect employees to go back to their cubicles and offices in the months ahead.

Other companies, most notably those in technology and media, are being more flexible. As much as Mr Gross wants people back at his ad agency, he is worried about retaining young talent at a time when churn is increasing, so he has been making clear there is room for accommodation.

“We’re in a really progressive industry, and some companies have gone fully remote,” he explained. “You have to frame it in terms of flexibility.”

In a recent Conference Board survey, 55 per cent of millennials, defined as people born between 1981 and 1996, questioned the wisdom of returning to the office.

Among members of Generation X, born between 1965 and 1980, 45 per cent had doubts about going back, while only 36 per cent of baby boomers, born between 1946 and 1964, felt that way.

And if anything, the rise of the Delta variant of the coronavirus may fuel resistance among reluctant office goers of all ages.

“Among the generations, millennials are the most concerned about their health and psychological well-being,” said Ms Rebecca Ray, executive vice-president for human capital at the Conference Board. “Companies would be well served to be as flexible as possible.”

Mr Matthew Yeager, 33, quit his job as a Web developer at an insurance company in May after it told him he needed to return to the office as vaccination rates in his city, Columbus, Ohio, were rising. He limited his job hunting to opportunities that offered fully remote work and, in June, started at a hiring and human resources company based in New York.

“It was tough because I really liked my job and the people I worked with, but I didn’t want to lose that flexibility of being able to work remotely,” he said.

“The office has all these distractions that are removed when you’re working from home.”

He added that he would also like the option to work remotely in any positions he considered in the future. “More companies should give the opportunity for people to work and be productive in the best way that they can,” he said.

Even as the age split has managers looking for ways to persuade younger hires to venture back, there are other divides. Many parents and other caregivers are concerned about leaving home when school plans are still up in the air, a consideration that has disproportionately affected women during the pandemic.

At the same time, more than a few older workers welcome the flexibility of working from home after years in a cubicle, even as some in their 20s yearn for the camaraderie of the office or the dynamism of an urban setting.

When they work apart, younger employees lose chances to network, develop mentors and gain valuable experience by watching colleagues close-up, veteran managers say.

In some cases, older millennials like Mr Jonathan Singer, 37, a real estate lawyer, find themselves making the case for returning to the office to sceptical younger colleagues who have grown accustomed to working from home.

“As a manager, it’s really hard to get cohesion and collegiality without being together on a regular basis, and it’s difficult to mentor without being in the same place,” he said. But persuading younger workers to see things his way has not been easy.

“With the leverage that employees have, and the proof that they can work from home, it’s hard to put the toothpaste back in the tube,” he said.