I don't think people care AT ALL about FOSS, however, they do care somewhat about privacy and sovereignty.
But at the end of the day, they need to have the network of people they care about already on the platform and they need a smooth experience.
I'm talking about the 90+% of people, not the people we all probably know. It's not about elitism either, it's just human nature. People care about the ends, not the means.
Even with all things being equal, if you offer X covered in shinies, you will win over someone just offering X. Companies like Meta are very good at covering their products with shinies, and governments are not.
You might think smart people will better well balance than not the poison in their drug to keep their junky customer base just afloat so business have a perennial flow of serfs. But even smart people are humans and make errors. And even if they plan with error rate in mind, they can be overthrown by one of their many far more stupid rivals. The number of mindless wannabe will always largely exceeds the anticipation power of the sharpest minds.
Its not really about FOSS vs proprietary. FOSS is better because it can be verified, but, for example, Whatsapp is better than a FOSS platform that is not E2EE and not decentralised.
Ideally we would use decentralised, E2EE encrypted FOSS.
Governments also like centralised platforms because they enable surveillance.
Clearly most people just don't care about freedom at all in general. They claim they do, but then will argue against anything and everything that provides even the tiniest measure of it.
... but you're not wrong, I'm afraid.