I do not see how a person making 50k € in Germany would have a gross/net difference of 50 %.

According to [1], the gross/net difference would be about 34 % in the worst case (highest tax class, no children, not married etc.), which includes social security, health insurance and so on. The calculator gives realistic results for my own income.

[1] https://www.brutto-netto-rechner.info/

If I enter 50k there, and a tax class 1, then I end up with

Netto: 2.456,06 € 29.472,66 €

which means 40% deductions. Which is approximately what I meant (yes, 50% was slightly too high).

You have to enter a value in the tax allowance field ("Jährl. Steuerfreibetrag"). The first 9000 € (if not married) a year are not taxed.

At 50k you are paying between 10-15% income tax.