I agree with Steven, but since I have this typed up I'll post it here.

Yes, iterability is another namedtuple feature. Although that would actually be easy to add to dataclasses, so I didn't mention it.

I don't really see the point of combining them, except for some conceptual purity argument.

You can already write a wrapper decorator which, given the various parameters to @dataclass, decides if it will produce a dataclass or a namedtuple. For example, there couldn't be any fields with init=False, or kwonly=True, the class would have to have frozen=True, etc.