Okay, I'll discuss. Would you have posted this if Jordan Peterson had said that Shintoism is "as sane as people can get?" And does it really matter what Jordan Peterson thinks?
The man is not, as far as he's ever said, a believer. What he claims to admire, here, "Catholicism," is quite a fantastically detailed and mammoth 2,000 year old "thing" which has a lot of concrete "thinginess" about it --- by which I mean, it is not something easily conformable to anyone's transient picks and preferences. It has its own definite content and character.
It's not easy to redefine, slip out of, or mold to preference. It's not particularly pliable.
It's not like, say, Buddhism, which is almost as old but not nearly as refractory.
As the subtle old joke has it,
"Christianity and Buddhism are a lot alike. Especially Buddhism."