Garbage trucks are probably one of the best places for it actually, because they stop so frequently. Unfortunately the article is about plow trucks instead which have a very different use case - New York just happens to use the same vehicles for both so they have a smaller fleet that's not as well suited to either task.
For garbage trucks you have stop and go movement so EVs eliminate idling. Given the size of the trucks it's probably not a big deal to make sure they have adequate battery capacity.
Plow trucks have a completely different use model where they're run at speed for long periods and one day of plowing could have the same distance traveled as weeks of trash collection. Hybrids would likely be an improvement in efficiency but the same way they do for other trucks - batteries support high demand periods while the generator is fine for the lower sustained loads.
Edit: a drawback of the smaller fleet for snow management is that garbage trucks aren't as well suited for salt/sand/deicer distribution. Nobody designs their garbage trucks to spray. I hope.
Edit2: garbage trucks also have a lot of additional mechanical systems that are probably already electrical, so among other things the ICE versions likely have an oversized alternator to power that.