[zavandor]

>So in Germany, the interest on a mortgage is non tax deductible

Wrong reasoning. It's tax deductable in Switzerland and they rent even way more than the germans

[TheCoelacanth]

But then you are also taxed on the imputed rent for the property, i.e. you have to pay taxes as if you are renting the property from yourself and the rent that you are paying yourself is taxable income. That greatly outweighs the effect of the mortgage tax deduction.