It really depends.

I know several companies offering 6 weeks of paid leave, plus holidays, in my area.

On the other hand, that's certainly not the norm. There are many people working jobs which provide no paid holidays or vacation.

At my previous job it was expected that you'd work overtime and weekends if anything remotely important was going on (and not get flex time or anything like that to make up for it) for no extra pay. At my current job there is no such expectation at all and nobody does it. Critical events wait until Monday.

My perception is things are especially bad in startup culture/the valley, but that's not necessarily representative of the US.

I think the real difference between the US and European Country X is the lack of any universal minimum standards in the US. There is the federal minimum wage and the FMLA, and that's about it. There is no federal requirement for paid leave or maternity benefits. But there are plenty of jobs with paid leave and maternity benefits (other than FMLA unpaid leave). So in reality, the work/life balance in America differs dramatically by locale, industry, and company.