"Yes, I am in shape (round is a shape)"

It's a social commitment at least as much as a creative/culinary one, and since there aren't a lot of people you'd want to give a pie minus a slice to, that keeps the extra calories under control.

I mean, yes, at worse you burn your neighbourhood down and your dog runs away. But in terms of the more likely failure modes like screwing up the dough, breaking it, messing up how watery it is, etc. you can mostly just keep baking until it's done, mix it up, put into bowls, serve with ice cream, down the hatch.

Any doofus can dump a can of pie filling into a pre-made crust and "make" a pie.