No advantages? So you don't count the smaller file size
and faster load screens as advantages? Not counting .NSZ files (because they take up the same space as an .NSP file once installed), .NSP files are the smallest versions of a game. .XCI files by default are larger due to being padded with empty data so they fit on cartridges. Its also been a well known fact that .NSP files also load faster than .XCI files. You can not only read the thread yourself
here but watch the videos the person recorded himself. .NSP files are far from "crippled" unless you download them from bad sources which is the fault of the uploader not the file. They are also far from incomplete as they literally contain the same contents as their .XCI equivalents, apart from some metadata. In fact, its .XCI files that are actually incomplete. According to Switch developer blawar, all .XCI files are missing some data that cannot be extracted with current means and that is due to lotus, the Switch cartridge reader, not being fully cracked. This means that if someone were to hypothetically make a Switch flashcart, all .XCI files would have to be redumped. If you don't believe, you can ask him yourself.