This isn’t the first time this has happened to her. Despite my best efforts to keep her storage in check (and all the cloud services that are supposed to help turned on), under typical use her phone will just eventually fill up. This experience isn’t just bad in that it misses that moment. When your phone hits zero space the device becomes horribly unresponsive, making the process of freeing up space cumbersome and time consuming.

https://david-smith.org/blog/2015/09/10/16gb-is-a-bad-user-experience/

I agree. It feels cheap that Apple’s default offer is with this amount of storage.