> They seem to feel a lot happier and healthier.
On average I would agree. I didn't see extreme poverty like I saw in the US and cost of living is a lot better when you consider that quality of everything is higher; especially in terms of food.
> They have better social mobility,
My experience is that this is not the case. Germany had almost no mobility at all. Even startups are structured in such a way that you can barely even see the CEO, let alone talk to them and society is structured to protect incumbents through regulations and bureaucracy. The only people who get rich in such system (like in Crypto sector) are extremely crony. Feels like they have some really weird agenda. The whole country feels like a giant money laundering scheme.
As for France; the salaries for software engineers were really low last time I checked. Might as well drive an Uber.