I have wondered many times.
Of course I can always use a browser but it’s overkill.
The same goes for yad or zenity, they pull in webkit which is a full-fledged browser engine, and at least yad does not have an offline mode.
I just want to look at some local HTML (incl. images) & CSS styling.
A more lightweight browser?
You gotta understand, browsers are designed to be HTML parsers. You can write an HTML file and double click to open in browser so?