Here is a contrived example that doesn't reflect reality:

There are 10 banks in a market. The banks have a range of new online services. Adoption of as many of these services as possible is the key to success. A viable strategy is to retarget customers (segmented by income/family status and other things that make certain services relevant) and tell them about various services. This increases the adoption of value add services substantially.

If one bank takes a moral stance, they either need to live with lower adoption of their services or spend more via less effective advertising channels.

If Facebook advertising is good enough, that one bank would go out of business, have its management replaced by shareholders or get bought out by one of the others.

This probably doesn't apply to banks, but there are businesses where effective online advertising is the difference between success and failure. All the tourist/hotel/flight booking sites, for example.