To be very pedantic, "Markdown standard" is basically a blog post written over 20 years ago and never updated.

Everything more "advanced" like tables, to-do lists and multi-line code blocks aren't a part of the "standard" as it was written, but were added on top by different implementations (like CommonMark) which are now commonly-mistaken for the original Markdown.

My point being that this isn't something unique to Obsidian, pretty much everyone does it slightly differently while still calling it "Markdown".