[ocdtrekkie]

I think you are misunderstanding my point.

An img tag doesn't work on an AMP page. It has to be an amp-img. Every standard HTML tag is invalid in AMP content, as you must use a customized AMP flavor of HTML.

Whether or not it returns valid as HTML markup isn't really relevant: The point is it's an entirely different, incompatible, markup, from what a normal browser knows how to interpret and use, and if your browser doesn't have JavaScript, it's not even going to know what any of those custom tags are, is it?

[joshuamorton]

That's not true, only tags that make web requests or do dynamic things are amp'd. You still use div and button and style and span and whatnot.

[SquareWheel]

There is an important difference between saying it is invalid html, and it is invalid amp markup. An img tag will work like normal. It just won't be a valid AMP page any longer.

>if your browser doesn't have JavaScript, it's not even going to know what any of those custom tags are, is it?

It wouldn't. <noscript> tags are needed for that. But Javascript is a web standard, and this is the correct way to create new elements.