For some reason I was having issues with some zip files. "Unzip" wouldn't unzip them, but ark (and perhaps other GUI archivers) would.
Fortunately ark can be used as a command line tool as well, which can be better than needlessly opening the full GUI just to make something so trivial. You still can invoke just the dialog, anyway.
But in order to extract something, for example, one can just use:
ark -b file.zip -o ./extantfolder