Nah, I think the run up right now is more about "The Next Tesla" than Rivian's actual upside. Pure FOMO more or less.
You are correct though, it's going to be years until Rivian posts a profit, and this is why I feel the fundamentals will reel the share price back down to more realistic levels soon, I'd guess by mid 2022 or so.
I'd never buy right now, I follow the theory of "be fearful when others are greedy" and right now pure greed is driving RIVN up. After it collapses, when fear of getting stuck bagholding drives it crashing down, THEN I'll think about possibly buying some for the long term.