It's been very hard on ancillary businesses in the centre of cities The worst aspects are that many will go to the wall and that wonderful after work life that I remember from working in London will be diminished, to be expected, sadly. I think there are a lot of fears it won't come back, thinking of theatres and the like.
I have had conversations with my son about it, as he is affected, hasn't been into the office for months. He and his girlfriend both work in publishing, their employers are quite happy with staff working from home and for them all to continue like this for a while. Depending on the type of business a company is involved in, if it has been viable for them to not have their employees in the office, I think it's safe to say they will have saved a lot of money in what they have to provide for the working environment. So much so, I imagine they must aske themselves do they need very large, prestige offices, or could they manage with smaller spaces, particularly if they are to stagger how many staff they have in at any one time, which will leave a hell of a lot of empty office space I imagine.
The upsides from working from home my son tells me is that he and his girlfriend are saving a lot of money they would have spent on their commute, most people who work in London have to go a good few miles out to afford to buy, or even rent, the cost of season tickets are ridiculously expensive. He also tells me they have a better work/life balance, previously they were usually out of the house from 7 am to 7 pm. A few downsides at times he misses the dynamic of working with colleagues and the after hours get togethers, and when working from home it's can prove difficult to have a proper division between work life and home life. They both tell me that the "Zoom meetings" can be continuous and intense some days and it's hard to wind down.
Clearly Covid has exacerbated the writing on the wall, I think there will be a limited return to the office in due course not sure things will go back to the way they were.