A little bit... but more, in the lack of backwards compatibility. I get it, legacy systems are painful. But I could see the server depending on the client send

A little bit... but more, in the lack of backwards compatibility. I get it, legacy systems are painful. But I could see the server depending on the client sending 2 variations. The modern one with new standards and heavy libraries, and a minimalist one with classic standards for old devices. It's a shame AMP didn't went for something like this, and instead went for their own weird standard https://xkcd.com/927/ https://xkcd.com/927/ .