Totally agree. It's ads and the attention economy. They thrive on controversy - it's the psychological version of the banner ads in the 90s, but 10,000x more effective.
When your company spends millions on advertising, you have teams of people to figure out if your strategy is effective.
Follow the leaders.
I've seen plenty of McDonald's ads online. Coca-Cola, usually around Christmas and the Super Bowl. P&G? Occasionally, but probably more often than I realize because it has so many brands.
That's one statement I can not believe. But it might be the case that I have not indeed seen the ads from those companies, maybe because of where I am.
Some medium sized companies will test with an ad platform, find the best performing sites and make deals with them directly.