/e: I'm a bit out of this game for 2-3 years now, but Python had nothing comparable. Prophet is suboptimal at best. Some things are implemented here or there, but it's all over the place. So I agree that R really shines here.
I would generally prefer R for this kind of stuff as the experts generally write the code, but Darts seems OK and is well-tested, at the very least (haven't had a chance to use it in anger yet).
This is in part why we built Darts. Now I think we can say the situation is quite different. Darts offers many things offered by the R forecast package, and then some (for instance the ability to train ML models on large datasets made of multiple potentially high-dimensional series).