The titano is a time limited mount. Amarg sucks. Diplo has no real use and the bronto is nothing more than a gatherer. We have no end game herbs. Let alone good sauropods.
So what if there’s Carchs/gigas? They’re carnivores. Tusos and mosas are limited to the ocean (and the mosa ain’t that great).
Your logic on why we don’t need this, is only terrible.