As mentioned in the sibling comments, Andrew Gelman has covered this elsewhere. In particular, Gelman et al have a "Model Checking" chapter in their Bayesian Data Analysis book https://sites.stat.columbia.edu/gelman/book/BDA3.pdf . A popular intro Bayesian book Statistical Rethinking has a similar "Sampling from the Imaginary" chapter (https://civil.colorado.edu/~balajir/CVEN6833/bayes-resources...). Both books introduce the topic early (the latter book deals with it in the third chapter) if you are willing to do a bit of reading.

Wait a bayesian advocate using a frequentist approach and not having a fight over which branch is supreme. What's happening with the world. I guess all stats united against AI.

From your description, I thought “wait, is this going to be Andrew Gelman?”

It is.

(For context: https://youtu.be/ZmbrsbYwRWw )

You were just one click away from finding out:

"Figure 2. Using a sample of 2,972 respondents from the National Longitudinal Study of Adolescent Health, each of whom had been rated on a five-point scale of attractiveness […]"