The hardest part of interstellar travel assuming it is done by organic life forms won’t be getting there — it’ll be creating an engineered ecology sustainable enough to allow long-term voyages of more than 10 years. The drive technology, if we pushed, we could probably have in 20-50 years for 10%+ of c travel. That’s just enough for interstellar voyaging.

But the eco side of it? We’re not even close.