In Switzerland this fictional imputed rent is actually extremly real. We have to pay taxes as if it was earned income.

So you live in your fully owned flat, pretend to rent it to yourself and then pay income taxes on that amount. The point is your government can make this "fake" value very real.

Luckily we recently voted to abolish this tax so it will be gone in some years. This tax was introduced as an emergency measure in ww1.