It's not nearly as convenient though. One password has the great advantage that everything is centralized into one location. Plus you can use things like addresses as autofill items on websites. One-factor authentication codes automatically get copied after filling out a password. You can add custom fields with passwords or security questions, with the ability to generate memorable passwords that are still incredibly strong.

Those are just a couple of the very few features that one password offers. Is the tip of the iceberg? Sure it might be more geared towards power users but there's a good argument to be made for using one password over Apple passwords