> have https but that was more of a vanity from what I remember
It has a functional difference as well, lots of new client-side features (like webcrypto) only work on "Secure Origins" which .onion isn't, but websites behind TLS are. So if you wanna deploy say something that encrypts/decrypts something client-side on .onion, you unfortunately need TLS today otherwise the APIs aren't available.
Of course browsers could fix this, but I don't think they have any incentives to do so. I guess Tor Browser could in fact fix this, and maybe they already do, but it'd be a patch on top of Firefox I think, something they probably want to do less off, not more.
It has a functional difference as well, lots of new client-side features (like webcrypto) only work on "Secure Origins" which .onion isn't, but websites behind TLS are. So if you wanna deploy say something that encrypts/decrypts something client-side on .onion, you unfortunately need TLS today otherwise the APIs aren't available.
Of course browsers could fix this, but I don't think they have any incentives to do so. I guess Tor Browser could in fact fix this, and maybe they already do, but it'd be a patch on top of Firefox I think, something they probably want to do less off, not more.