Which is why we have elected officials run cities rather than property developers. The goal is not to make a profit today. The long term goal is a pleasant city with happy residents. Look at the Spanish neighbourhoods that were overbuilt only to be abandoned when the bubble burst. Think gentrification is bad? When an underused building looses its value it becomes blighted, saddling the city with all sorts of social problems.
I've heard some cities thinking about imposing a supplemental tax on unoccupied housing. It would help a lot, not just in skyscrapers but also in low-density areas where slumlords let their houses rot waiting for the land values to rise.
But unfortunately, the same people who would get hit by this tax are the most solid part of the tax base. Real estate taxes are a huge part of many cities revenue. Increasing them is never popular.
British Colombia already has an "unoccupied home" tax.[1] Of course Canadians who bought a vacation home in BC are getting the shaft. 2% of the home's value for a foreigner.
[1]https://www2.gov.bc.ca/assets/gov/taxes/property-taxes/publi...
Vancouver has many layered issues. I'm no fan of building more apartments only to have them sit empty 90+% of the time. Much/most of Vancouver's current multi-unit capacity is underused either as second homes or as investment vehicles. Building more will make current owners rich, but I say we shouldn't do than until we are better-utilizing current stock.
The percentage of single-family homes that are either empty or under some form of construction amazes me. I walk through neighborhoods I grew up in that are now practically empty but for carpenter's pickup trucks. These are no longer residential neighborhoods. They are industrial zones where workers commute in to 'mine' real estate.