The irony is that the people complaining about this are the same ones who are gleefully sharing their personal details and narrative on social media, and Facebook in particular. The only difference between mass surveillance in the US and China is that 99% of the US population happily opts in or doesn't care.
I don't disagree with you, but government compulsion makes this a different animal entirely. The bigger context is that in the US, there is SUPPOSED to be a system in which companies can successfully resist government demands (remember that Apple did this to the FBI when they wanted to crack a criminal's phone passcode), whereas in China, that cannot happen. So yes, people give away their data for stupid conveniences…
Saying that "Facebook/Google etc aren't supposed to share the data with the government" only makes sense in some abstract sense of it wasn't supposed to be like this. But power tends to coalesce - the only "supposed to" is in some abstract moral stewardship sense, a responsibility that has been long forgotten by the business community, if it ever existed in the first place. Facebook/Google want to agglomerate data from the financial surveillance bureaus, and the (nominal) government buys the proceeds from both of them in a "free market" transaction. And then on the output/control side, companies use these surveillance databases to weed out "undesirable" customers, with their competitors following in lock step lest they end up with even more undesirables.