
why can not use?
I am not sure whether it is a good choice to forbid self-closing tags by default. W3C html5 standard allows self-closing tags when they are void-elements or foreign elements:
https://www.w3.org/TR/html5/syntax.html#start-tags

Customized vue components, although not covered by html5 standard, might have no reason to disallow self-closing, I think.
In fact both nuxt and quasar recommend self-closing components when there are no slots in them.
Agreed with @beeplin -- another example is image and line break tags.
Most helpful comment
I am not sure whether it is a good choice to forbid self-closing tags by default. W3C html5 standard allows self-closing tags when they are
void-elementsorforeign elements:https://www.w3.org/TR/html5/syntax.html#start-tags
Customized vue components, although not covered by html5 standard, might have no reason to disallow self-closing, I think.
In fact both
nuxtandquasarrecommend self-closing components when there are no slots in them.