I'm not sure I follow your argument, because, first, no major browser maker is in the business of selling their web browser software, and second, if you're using the browser maker's software to verify the server, you already have access to it. So even if they were selling it, you've already paid for it.
Google's self-interest does factor into these decisions, though: Google's interest is in making more people use and trust the internet. The more people who feel comfortable buying things online, for instance, the more ads they'll click from online sellers. The more businesses who feel comfortable selling things online, the more ads they'll buy, and thus the more profit Google will get.
So it's important to Google that the internet remains perceived as a secure and trustworthy place to do business. If users are in the business of making judgment calls about certificates, some fraction of the time they'll be wrong - and they aren't going to say "Oh, I made a mistake," they're going to say (correctly, even) "Oh, doing secure transactions on the web is too difficult."
There are a whole lot of ways in which Google's interests are badly biased against end users, and as you mention FLOC is a perfect example. Wanting the web to be secure is not actually one of them, though.
Google's self-interest does factor into these decisions, though: Google's interest is in making more people use and trust the internet. The more people who feel comfortable buying things online, for instance, the more ads they'll click from online sellers. The more businesses who feel comfortable selling things online, the more ads they'll buy, and thus the more profit Google will get.
So it's important to Google that the internet remains perceived as a secure and trustworthy place to do business. If users are in the business of making judgment calls about certificates, some fraction of the time they'll be wrong - and they aren't going to say "Oh, I made a mistake," they're going to say (correctly, even) "Oh, doing secure transactions on the web is too difficult."
There are a whole lot of ways in which Google's interests are badly biased against end users, and as you mention FLOC is a perfect example. Wanting the web to be secure is not actually one of them, though.