Containerized Garbage is something that sounds really good, but there's always unexpected consequences to new policies.
Here's a quick stab at some of them.
1) Less Safe Roads. New Yorkers in many areas have to drive around for half an hour or an hour or more sometimes to find an open parking spot. This already leads to deeply frazzled nerves and unsafe driving as drivers scoot around oblivious to traffic and pedestrians to try and find a spot. I've seen drivers down main streets see a spot open up and immediately try and do a U-Turn into oncoming traffic, or just gun it through an intersection to try and be the first one to grab an open spot. Remove 5% of parking spaces, and this stuff increases. Maybe more people will get hurt in pointless accidents.
2) Fewer Spots lead to more parking tickets. These are of marginal impact on the well-off, but a struggling person who receives an unexpected ticket is completely fucked. The same people who claim to be on the side of the downtrodden and struggling classes truly ignore the actual impacts of their social engineering on those people. And as much as you might not like cars, many people have employment or childcare needs that depends on them.
3) Air Pollution and waste of gas. Garbage on the sidewalk is unsightly and horrible to see, but there's more than one kind of pollution. As mentioned, there are areas in the city where it's routine to drive around 30-60+ minutes to find a parking spot. Now increase all of this by a percentage, and more cars will be spewing exhaust fumes for longer. Is it a real win to tradeoff cleaner sidewalks for dirtier air? Maybe that's the best tradeoff, but I think it's important to recognize that there might be a tradeoff.
Despite all of this, I'm not saying that containerized garbage isn't a good idea. I'm just playing a little devil's advocate here. But just wanting to point out a different perspective that there's always some ignored bad that comes with every good.