I think they meant that Apple’s updates seem to be the opposite of incremental, and they’re not wrong. If anything, Apple has moved in the exact opposite direction in the past decade, moving towards using enormous cryptographically-signed volumes (“sealed” is the term). This makes Apple really happy because they can make sure the users aren’t allowed to modify any of the “system“ files themselves for any reason, but also means that they can’t incrementally update things as easily as they did before. They ship multi-gigabyte “patches” every time.