Excuse me, in that video the second gentleman inherited a building bought in the late 50's. Meaning he has no mortgage, his costs are tax, unit related maintenance and the legally required renovation costs.
The apartment has stayed "untouched since the tenant passed away". It's clearly is still full of stuff of the deceased! I would understand if there's a big renovation needed (e.g., Asbestos removal, a hard to fix leak, replacing the entire plumbing/electric, etc.) but certainly one would've at least cleared the place oneself if the money is tight.
The non-controlled apartment he shows doesn't seem that different beyond aesthetics, sure the modern lighting and new paint job looks nice but the windows are just single-pane like the mothballed unit. I find it telling that he doesn't mention any specific issue, or that he frames not breaking even on the first month as shocking. I've seen plenty of NYC apartment tours in the internet of random 20 somethings. A lot of them didn't look like they were renovated in this millennium.
Isn't by definition, a landlord a property investor? Is it some tragedy if he has to invest and wait for a return? The building has been in his family for close to 70 years, did they do maintenance and renovations proactively? If he's so strapped for cash and doesn't have the cashflow or credit to repair the building, why doesn't he sell? Even if the price is lower because the rent control, the asset appreciation since the Eisenhower administration must be absurd.
Yes, the actual solution is building like crazy, but is kinda insulting to blame rent control while showing landlords crying woe is me and sealing apartments with the tenant fresh in the morgue, transparently making a bet that rent control will be repealed because they are letting their units to rot.