I am genuinely curious every time the topic of chopstick etiquette comes up

I'm not much of a writer, so I'll summarize a post I saw in the bullpen a long time ago. For the record, I'm not good at using chopsticks either.
1. In Joseon Dynasty records, where all sorts of trivial things were documented, there is no mention of chopstick etiquette.
2. Even when looking at paintings by masters of portraiture, you often see the "fist grip" or "X-shaped" styles that people criticize today. In fact, there are no paintings by artists depicting the "standard" method currently taught.
3. Among countries that use chopstick culture, there is only one country in the world that uses the exact same method as Korea—a country where people are even more critical if you do it poorly and where people supposedly call off engagements during formal family meetings because of it: Japan.
4. So, when a certain person uploaded broadcast footage and asked elders if such etiquette existed in their childhood, they uploaded footage showing that it didn't exist and suddenly appeared.
5. The conclusion is that it was introduced during the Japanese colonial period.
I'm really curious about what the truth is.
For the record, I'm asking because I got triggered by someone mentioning "family upbringing" or whatever, haha.