You can't say MOST... even before Covid there were already tons of people/jobs who work remote. Many sales type positions are remote and some jobs can't even be in an office just like some jobs can't be remote.However, I will bet everything I have that MOST people don't work as efficiently remote.
The one thing that in-office has that remote does not is direct oversight, and again, that still doesn't mean people won't just work as a "passing" grade in office either.
As other have said in this thread... companies are not bringing people back because they think it's better... it's because they already sunk the costs into office space and need to use it. And if you read the fine print... many of those big corps are not making them work in-office full time, many of them are hybrid because they understand the morale effect of remote work and the benefit of work/life balance.
I get it... I was like you 5 years ago where I couldn't understand why people just don't go into the office as I felt in-office workers are more productive. But times have changed and technology has evolved... remember what happened to Twitter when Elon forced everyone to work in-office... he even had to backpedal on that policy and make exceptions for talent.
But maybe that's what will happen... only the most productive people can work remote and all the slackers will be in-office... we will see how that works out.