I think that's a good point, but with the caveats that:
Immigration and benefits are in opposition - the more immigration you allow (unless it's careful, skills-based) then there's a strong risk of costs of living rises (e.g. housing becomes more expensive with immigration) and benefits systems requiring higher taxes to pay for them. European countries can sometimes be very strong on immigration (e.g. Denmark) likely because of this reason.
Entrepreneurialism and benefits are in opposition - the more benefits you offer, the higher the taxes need to be, and so the less worth it it is to take risks with money or with time. It's just a tradeoff between risk and safety, and Europe in general (or Western Europe, at least) is more tuned for safety. And why not, if the US is willing to take the risks?