The smallest ones are the most agile and the least to lose by going virtual.
Big ones however have a conundrum. If the company has spent tens or hundreds of millions of dollars building a giant headquarters, and then they go virtual or largely remote, then that money becomes basically a wasted investment. And so they have to admit to their investors that money was wasted, much of which can't be recouped even if they sell the building. That goes triple for companies with big campuses like Apple or Google. That's why you get a lot of companies demanding things like in office 3 days a week, to create justification for having the office in the first place.

There's also a simple human factor. A lot of management, even tech management, still has the attitude that being able to physically watch the employee somehow enables better control or management or increases productivity. It's crap of course, unless you have lazy unmotivated employees they will work just as well from somewhere else as they will with you breathing down their neck.

But it's caused some interesting shake-ups. A while back I read a great interview with a (fully virtual) tech startup CEO, he said whenever their bigger competitors announce RTO his HR department quickly buys a bunch of LinkedIn keywords targeting them.
He found, as almost anybody could figure out with basic logic, that the best and most valuable employees know their worth and thus are the first to quit rather than RTO, and his company is right there with an offer of 'work on some exciting new tech and we will never push RTO because we have no office to return to'. Said he's gotten some of his best people that way.

So when the bigger CEOs are now saying they don't see full return to office, I think that's because they are realizing they have no other choice, the labor market has changed and demanding full-time in person or even hybrid has become the same as a significant salary cut.