Another problem is there is still some weird idea in the West that Shodan (first degree black belt) is a teacher. This is simply not the case.
I'd rephrase that to "there is still some weird idea (among people all over the world) that Shodan (or any other rank) means or should mean the same thing across different arts, schools, and organizations."
In some schools, the expected requirement for a first degree black belt might be that you show up 2-3 times per week for 2-3 years, memorize some kata, demonstrate some techniques in tests, and do a bit of light sparring.
In other schools, the expected requirement might be that you spend 10-15 years pouring in blood, sweat, and tears, fighting and competing, and demonstrate the ability to win fights using a high degree of technical skill.
For some schools, the requirements might include practice in actual teaching and developing pedagogical skills. Others have no such requirements.
Many schools fall in-between those two extremes or even outside them. None of those standards are objectively "better" or more "correct" than the others. They're just different and if you want to know what (if anything) a person's rank means, then you need to know the standards applied by the person(s) who awarded that rank. BTW - I don't know that "high" vs "low" standards for black belt correspond to "East" vs "West" in any meaningful way.
(As a side note - the ability to teach is only loosely correlated with the ability to perform an art at a high level. If you want to become a boxer, you're better off learning from a Cus D'Amato than a Mike Tyson.)