Why is D's GC slower than GO's?

[Imperatorn]

On Sunday, 30 October 2022 at 04:06:40 UTC, ISO C with Modules 
wrote:
> On Sunday, 30 October 2022 at 00:36:23 UTC, Ola Fosheim Grøstad 
> wrote:
>> [...]
>
> So Zig (like all C replacement wannabeess..) IS meant to be a 
> higher level of experience of C?
>
> [...]

Why does D need to be standardized? I mean, it would be great if 
it was, but why would it be a "non-starter" otherwise?