Ditching HTML for CommonMark (like MarkDown but without any daring fireballs) would be better IMO. Then again, the designers of HTML had no idea what it would become when they carved out a subset of SGML for their document markup. If we were starting over perhaps a mix of XAML for app-stuff and CommonMark for text would be a good mix... unless that totally screws up i18n. "It is what we have and it seems to work" explains HTML somewhat adequately.
