He's not making that up; in practice, you're going to run into and need to make mental space for the idiosyncrasies of multiple error frameworks.

I guess you might have to if you need to use a library someone's written that doesn't implement the standard.

Writing primarily applications, I couldn't tell you what error handling frameworks my dependencies are using: I literally don't know, and haven't needed to know in order to display, fail, or succeed.

EDIT to add: I use anyhow for this, so I should also add "add context to an error when I fall" to the list of things I do.