Centralised offices, mostly in London WERE a blip, but offices in general weren't.
It's only a few decades ago that there were offices in every town, insurance offices, tax offices, banks/building societies, solicitors, accountants, etc etc. Some towns and small cities even had head offices of national firms, such as Provincial who had their head office in the small Cumbrian town of Kendal, plus lots of local building societies had head offices in small towns.
It was the 80s and 90s where "local" offices were closed and centralised in a handful of big cities, but mostly London. Then Brown in the noughties started the closure of local town centre tax offices!
The centralisation into London is partly what caused London to overheat in terms of housing shortages, transport costs/congestion, higher wages needed, etc etc.
At least when there were lots of offices in town centres, it helped "spread" the workers across the country and fuelled local spending in High Street shops etc., not just lunches, but "proper" shopping for groceries, clothes, household goods, etc.