The semantic Web was always a W3C boondoggle that never became part of the Web as implemented by browsers. So that's a bad example in this context. It's hard t

The semantic Web was always a W3C boondoggle that never became part of the Web as implemented by browsers. So that's a bad example in this context. It's hard to see exactly what you're asking for. Web specs are already quite modular. The modularity could be improved, but it's not like nobody's trying.