Taxes are a means for collective action. A government collects money from individuals and invests it in projects that cannot be undertaken individually and are required by society.
Advertising, specifically in the form of sponsorship, does the same.
You buy a brand which sponsors, say, a band, and part of your money gets diverted into that band's support. As brands become bigger and bigger and spend ever greater amounts to gain your attention, often with budgets that government departments (or even small governments) would envy, the power of collective action through brands is huge.
And so it becomes even more important for brands to define what they stand for.