But, you know if a business changes to dynamic pricing and their next quarterly numbers shows that the vast majority of people didn't swallow it, and revenue is hugely down, they would undo it in a second.

You would be right if we assume that

1. The people leading these companies are making informed data driven decisions.
2. Companies majorly made money through selling goods/services

However once a company is a certain size or in the correct position it's more about showing a growth potential to investors, then actually proffiting from selling goods/services. Investors is really how these companies make money now. I'm not an economist so I'm not sure if this is still technically capitalism when the majority of profits come straight from investors but to me it sounds much more like a ponzi scheme.

My point being is that in a best case scenario, a nationwide boycott could take place and a company makes $0 gross income. But they can still profit if they can convince their investors that they are taking the right steps to position themselves in "this new economy". Now realistically someone is still going to buy their products and any boycott effort will just have minor effects. The absolute worst case scenario for anyone actually in charge of making decisions like this at a large company is they get a golden parachute and hop over to another place.

Just like you said, why would they turn down free money?