I think there’s more nuance than that is the issue. The average European likely has a better QoL than the average American. If you go above average in wealth/salary, the US can be great.
Well my meta point was more that framing an apparent consensus as an "asymmetric conversation" seems pretty motivated.
But to respond to your point, most everywhere is great if you're rich enough. Saudi Arabia is pretty rad if you happen to be in House of Saud.
Your observation: Online, Europeans assert they have a better quality of life than Americans, while Americans do not assert the reverse
Your conclusion: "idk maybe they're lying???"