9-10 words chosen at random from a list of 10k common words in you native language will get you to 128 bits. Sure not trivial to memorise, but far from impossible.

You're not wrong of course - this would come with heavy UX issues though. E.g. it's hard to type 10 words into a password field without messing up. And _really_ hard on a mobile device.

1P would allow you to have a password like "1234" and still have the same key entropy as that 10 word password alone.

A mobile app could easily facilitate that by storing a "passphrase prefix" (or suffix, etc) using biometrics/device key and requiring users to enter the remainder if you don't trust the device to store the entire thing.

Here's a 142bits entropy password: CorrectHorseBatteryStaple

Also see: https://xkcd.com/936/

Depending on dictionary size, the entropy is way lower. Assuming a dictionary of 10k words, it’s only 53 bits.