Parsing HTML is anything but a minefield. It’s far and away the best format in this regard that I’ve ever encountered, because its parser is defined exhaustively, and all the tools people use obey.¹ Few other things boast that, and even fewer are consistently implemented correctly (which is to say: I don’t know of any examples, though I haven’t hunted).

(I’m speaking specifically of parsing HTML. Other tasks that you may perform on documents are a good deal less robust.)

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¹ OK, so developers often still use bad HTML parsers in their own apps. But browsers and all good HTML tooling gets it right.