Welcome to 1999! XHTML has been created exactly for this reason, and that's even where the self-closing idea came from.
HTML5 syntax hasn't been designed, it's been reverse-engineered from the mess HTML has become while the XHTML has been failing to get proper (XML parsing mode) adoption.
The other nice thing abuot xhtml is you could generate it with xslt. So your AJAX calls (returning results as XML in those days) were easy to format for display and easy to sort, filter, and query without making another round-trip.
HTML5 syntax hasn't been designed, it's been reverse-engineered from the mess HTML has become while the XHTML has been failing to get proper (XML parsing mode) adoption.