I think the commuting into the office every day has (un)fortunately, run its course. I'm a bit torn about it as I personally love being in the office with colleagues, but the commute can be a bore (although you always get a seat at 530-6am). You can't beat inter-personal connections in the face to face world - but I suppose it depends on your sector. However, I won't deny that being at home 2-3 days a week is not welcomed.
I can't support JRM at all - there's a lot of office/admin work that can be done at home (that said, I'd expect proper desks/office space to be set up for workers and not be sitting on their kitchen tables) - and I'm sure the admin-stuff that the .govs are doing can mostly be done at home. Does that mean it should be exclusively at home? No, but trying to get everyone back in all the time isn't going to happen now that people have had the pleasure of working in their pyjamas and creature comforts. At best he can try and mandate a number of days a month in the office, but expecting 100% attendance every day is just going to move people to more flexible companies. And to further counter that mug, more people are now working for companies they never would have before, i.e. if you live in Wales, you can now work for a company based in Edinburgh without issue - this is important as you diversify your workforce and create a different element of value that you wouldn't have had before.
The only thing I will say, is that if people don't ever go into the office, there's a significant (in my opinion) social knock on effect of people forgetting what it's like to interact with people not just socially but in the business world. That said, seeing how busy London is these days I think the majority of people are now back in the office at least a few days a week, I think it's still a fairly small chunk of the sectors that have an "exclusively from home" contract.