You use HTML5 query selectors, not xQuery. You don't use your generic XML tools, you use generic HTML5 tools. As for "why learn them so I can drop a few tags":

You use HTML5 query selectors, not xQuery. You don't use your generic XML tools, you use generic HTML5 tools. As for "why learn them so I can drop a few tags": because you don't, you make the tooling do it for you. Because that's what tooling is for. If you need XML: use XML tools. If you need HTML: use HTML tools. If you need XHTML... you're writing web content for IE, and IE is dead. XHTML died with it. Feel free to stick with what you know, but that's a pretty ridiculous argument for why you shouldn't use the thing that's used these days instead of the thing we used 15 years ago =) (hot damn, 15 years. It's been longer than most folks realize).