> they wont just lose that customer - they'll lose thousands of others too
No, they won't. And that's the problem in your argument. Google landed in court for tracking users in incognito mode. They also were fined for not complying with the rules for cookie popups. Facebook lost in court for illegally using data for advertising. Did it lose them any paying customer? Maybe, but not nearly enough for them to even notice a difference. The larger outcome was that people are now more pissed at the EU for cookie popups that make the greed for data more transparent. Also in the case of Google most money comes from different people than the ones that have their privacy violated, so the incentives are not working as you suggest.
> Going through life not trusting any company isn't a fun way to live
Ignoring existing problems isn't a recipe for a happy life either.
Landing in court is an expensive thing that companies don't want to happen.
Your examples also differ from what I'm talking about. Advertising supported business models have a different relationship with end users.
People getting something for free are less likely to switch providers over a privacy concern compared with companies is paying thousands of dollars a month (or more) for a paid service under the understanding that it won't train on their data.