Things that can never be done remotely: agriculture, construction, manufacture, hospitality, a big part of health/elder care, a big part of education, anything that requires expensive equipment (research, ...), artists/shows/events, the list goes on.
A lot of these sectors were either closed or running slow during COVID, which was not sustainable (you can't maintain the purchasing power of an entire population for decades if suddenly half of it stops working - it only works for a short while if you expect to be able to repay the debt you incurred to keep non-working people afloat).
So even if every single person that can work remotely does so, still expect big cities with transportation issues.
And that's without counting all the jobs that can be done remotely but are better done in office.