I'll try to dig it up, saw it a while ago on a forum.
Another thing might be that in Rubin's framework it's immediately straightforward to do semi-parametric estimation and get consistency and all that. I'd say in practice that's probably not the first thing to do for DAGs, where writings are focused on toy models (the question then would be: how do I get to the correct DAG?).
Edit: This was posted itt, it has some examples of Rubin's framework (potential outcomes) that can not be identified in the DAG framework
https://arxiv.org/pdf/1907.07271.pdf
Example?