If Google/Meta/Youtube want to be multi-trillion dollar monopolies that have invaded every aspect of our lives then there should be some very basic corporate responsibility that comes with that power, even if its difficult and maybe even costs them a little bit of money. Lately it seems like the phrase has been inverted to "with great power comes less responsibility". If your small local TV station ran ads for cocaine and synthetic opioids nobody would be making these kinds of excuses.
Aside from YouTube, there’s an alternative for all of the services provided by Google and Meta. Fastmail, X (Twitter), a billion different messenger apps, Microsoft apps for office applications, etc etc.
A company doesn't need a literal 100% market share to have monopolistic power. Products like Google Search or Gmail that dominate their respective markets count.
Google and Facebook are ads companies. Everything they build, deploy, do, share, sell, and buy is about selling ads. Youtube is a platform to sell ads. Gmail is a platform to collect data to sell ads. Facebook is a platform to collect data to sell ads on Facebook. Both companies have "analytics" products that exist to collect more data for ads.
What competition is there in the Ad space for internet advertising?
Yeah, all the socialized losses from business have fallen on governments and citizens to pay for it, and figure out how to do it. Superfund sites always spring to mind but we seem to have socialized costs oozing out of every business. Capitalists should abhore this type of gross inefficiency. In theory the business could solve the issues internally: cheaper, faster, better than the government could ever hope, lowering the overall tax burden and ultimately preventing problems at the source.
Regulation is very expensive because you have to enforce it. You can tax anything, though. Maybe that is a better route to promoting good behavior "voluntarily."