If your argument is somehow that Rust, C++, Nim, D or some other alternative would do better in terms of on-ramping I can only shake my head and move on with my day, as they are all clearly much more complicated languages and they all happen to produce code that is much harder to understand from a performance perspective. If the argument is something even higher level and even more opaque in terms of performance-related behavior I think you've missed an important part of why Bun chose Zig.

In most cases that don't involve "I already know this language" the equation can never be much better than "You have to learn Zig/Odin". For every person that already knows the language in question there's a bunch that don't, and the only solution to that is quick on-ramping because it'll benefit everyone over time. It doesn't matter whether you know the language already if the language is mostly trivial to learn, read and use.

P.S.: If the argument is that C would be a better choice I don't disagree as wildly as I do with any of the other situations. C with custom allocators and a ton of static analysis added to it will be mostly fine, but both Odin and Zig provide great things on top of C in terms of basic language features without taking on too much complexity.