I can see how one might naïvely think that, but in my experience and the experience of everyone I’ve talked to who uses julia, gradually improving the performan

I can see how one might naïvely think that, but in my experience and the experience of everyone I’ve talked to who uses julia, gradually improving the performance in your bottlenecks using only Julia is much nicer that just working in C or dropping down from python to Cython. You can improve much more gradually as needed, retain all the full language features and have much less menta overhead, needing only to keep Julia in your head. Julia devs make performance regressions when replacing critical central code components just like everyone else does. The advantage is that julia makes it easier to reason about and fix those regressions