We once went on a tour of Manhattan. Saw a bunch of brownstones that had been burnt out, boarded up, exterior in place, not renovated. I asked our tour guide about them. He said they were all rent controlled and it cost far more to repair them than they would get on rent, especially when taxes were considered. It was suspected that more than once the property owner actually had the building burnt, but they couldn’t prove it.
Unfortunately, NYC needs another ~15 years of market rate construction.
DeBlasio and other pols want to stop that.