I think the point is that it is the blessed/default way of doing things, rather than opt-in, as in C++ or Rust. Rust doesn't even have a good allocator interfa

I think the point is that it is the blessed/default way of doing things, rather than opt-in, as in C++ or Rust. Rust doesn't even have a good allocator interface yet, so libraries like bumpalo have a parallel implementation of some stdlib types.