I'm not an expert and I don't want to be one, I just want to have access to quality tools (preferably open source) and I want the majority of developers to use

I'm not an expert and I don't want to be one, I just want to have access to quality tools (preferably open source) and I want the majority of developers to use those tools. Native UIs are efficient, web UIs aren't. It doesn't matter to me that they're built using painters, batch drawing or pixie dust as long as the API is sane and performant. I think your post is a nice summary of the thinking that got us here in the first place: experts always looking at the possible future optimizations and not stopping to think at the present quality or if it's at all reasonable to build complex UIs in a document mark-up language.