I think you're exaggerating his policies. He's not proposing "rent control", he's saying he won't raise the rent on existing rent-stabilized apartments. To conclude that limits supply assumes that all the extra money would be invested into new construction.
Likewise, he's only proposing a pilot program with five grocery stores, which isn't a huge capital expenditure for a large city.
That's kind of a joke right? it's a pilot program for 5 grocery stores? he wins votes off something that is something you admit is so inconsequential, while spending political capital to do it instead of other things? 2% margins baby
Those apartments are already under rent control, and they'd be just as rent controlled if he allowed a rent increase. So, if "rent control limits supply", the supply will be limited no matter what he does.
My mistake, I thought you meant financial capital. I disagree. It seems like grocery prices are a real problem in New York, and the existing subsidy program isn't working. Ensuring people can afford food seems like an excellent use use of political capital, and if it works it can be scaled up.
Likewise, he's only proposing a pilot program with five grocery stores, which isn't a huge capital expenditure for a large city.