Could you explain what you mean about the incentives from tax and accounting policy? Are you saying that tax benefits for having office space are richer than the actual expense of renting that office space?
Those are not necessarily solely financial incentives, but they function to compound and combine with already established systems of corporate organization, personnel structures, and general status quo operations and processes. In that scenario, the co-located work paradigm was not only supported and strengthened where remote working was not, but it also set an expectation that thar be government breast milk in tumultuous times.
I am no corporate tax, accounting, or financial expert; but what I can say is that it seems to be the forest that can't be seen for all the trees.
eg.
$10,000 in gross profit - 20% in taxes = $8,000 net profit
$10,000 in gross profit - $1,000 rent = $9,000 - %20 taxes = $7,200 net profit
The net rent was $800 instead of $1,000 but not free.