There is also the opportunity cost of the owner not living in the domicile and not paying those same taxes, at probably higher amounts than the squatter. The owner is probably wealthier than the squatter and thus will pay more taxes.

Squats usually end up in houses where no one cared in any way for years and some times, like the recent short-term squat in Munich, for decades.

And the only interest which the "owners", mostly in form of offshore companies, have is to make huge amounts of money at the cost of the city, so I don't have a single tear left for them.