[jefb]

I think we're largely in agreement here e.g. I agree 100% that premature abstractions hold a lot of inertia. I'm just advocating for making decisions that optimize for "the right thing" over speed alone. In my experience the right thing tends to be adaptation, but that's because I do a lot of R&D work.

Sometimes yes, you can eat your cake and have it too w/r/t performance and flexibility; but the choice of programming language cannot be categorically relegated to "always pick the fastest one". There are no silver bullets, there will always be tradeoffs.

Flexibility matters, ecosystem matters, developer experience matters, third party libraries matter, good requirements (or lack thereof) matter, budget matters, timeline matters, security matters, and yes, performance also matters - it's just not the only consideration.

High level design decisions, language included, are not "pessimized by default" because they deem some of those other considerations more important than speed.