Of course life at a deep level is just physics. But given that the information content of this signal is relatively low (regular patterns of repeats) and that the amount of energy it requires is immense, I'd bet much more heavily on a natural phenomenon than life-directed activity.
I’m not saying there’s evidence, I’m just pointing out that it’s a strange dichotomy to say that one one hand, we have explainable phenomena, and on the other hand we have extraterrestrial life. If we ever do find proof of it, I don’t understand why the assumption should be that it won’t be explainable.