https://www.apple.com/ca/business-docs/iOS_Security_Guide.pd...
> The “Erase all content and settings” option in Settings obliterates all the keys in Effaceable Storage, rendering all user data on the device cryptographically inaccessible.
Semantics debate around whether leaving data practically inaccessible is the same as removing it, but considering where we are, I'd say it isn't.
Granted, this is from 2018, but I doubt the defaults and concept have changed.