I find it weird too. I’ve always considered cookies like very stupid key value stores.

It would never occur to me to put something more than a simple token in a cookie. A username, and email address, some opaque thing.

The idea of trying to use it for arbitrary strings just seems weird to my intuition, but I don’t really know why. Maybe just because when I was learning about them long ago I don’t remember seeing that in any of the examples.