100% this - but good luck fixing that, since the people who'd have expected contenteditable to work are the ones that want to unify input and output... so it's

100% this - but good luck fixing that, since the people who'd have expected contenteditable to work are the ones that want to unify input and output... so it's an intractable mess you basically want an UI for inputing and validating some schema-enforced JSON, but that's overwhelming and overkill for most users and more apps, so you script into existence a simplified version of that (aking to "everyone who doesn't learn lisp is cursed to reinvent it" or smth like that but for frontend devs).