Why does no one do the simpler thing? Because there’s no extra value to it, and it in fact has negative value because then the team has to write and understand it and the rationale for the departure from just using the same component library everywhere.
“Only a few kb of javascript” may as well ZERO javascript, and because of that it’s not even close to the top thing to optimize on your favorite site.
So, you engineered a non-standard radio button that is different to the rest which all use shading?? Why weren’t you building features that you know.. make money?