I'm not a full-time Gopher but I had a similar thought a few weeks ago, this idea of just having template partials for components and maybe a function constructor. Templ has a similar feeling but you can get most of what you want with pure Go. In Ruby-world there's the ViewComponent pattern/lib that Github came up with, a sort of HTML non-JS component, but I just can't really see why you need more than simple functions to do it.
Haven't thought it all the way through, I expected the code to come out a little bit cleaner but Go being a bit more explicit is for the better, not much one can do here.
But it's a valid idea: 80% of JS component libraries are just reimplementing "" as "" with no added value atop the HTML.