The numbers are similar for other western economies.
Okay...
> ... add extra money from increased taxes (make it flat 50-60%)
No. You can't presume anything about increased revenue from extra taxes. If you taxed income for any amount of work at 50% and you give every "household" 42,000€ (which I assume is livable in NL) you would drastically reduce the incentive to work and pay taxes, so your actual tax revenue goes down.
> The numbers are similar for other western economies.
The numbers generally say that if you pool all the social spending, you can redistribute it to everyone and it will pay for a subsistence level of living. However, a big part of that pool is pensions, which are liabilities in proportion to the amount paid by the individual. A lot of pensioners would be subsidizing people who never paid into the system. That's the main problem.
Good luck passing a bill that raises my effective tax rate from 17% to 55%. Obviously if you take a whole lot more money from everyone else there will be more to hand out to others.
Also remember you counted in pensions into your budget, those are separate from taxes. So the net profit from working would be maybe 30% or less - ridiculous!