I honestly think if Walter Bright (or anyone within D) invested in having a serious web framework for D even if its not part of the standard library, it could be worth its weight in gold. Right now there's only Vibe.d that stands out but I have not seen it grow very much since its inception, its very slow moving. Give me a feature rich web framework in D comparable to Django or Rails and all my side projects will shift to D. The real issue is it needs to be batteries included since D does not have dozens of OOTB libraries to fill in gaps with.
Look at Go as an example, built-in HTTP server library, production ready, its not ultra fancy but it does the work.