[cangeroo]

It goes against the principles of the semantic web

https://en.wikipedia.org/wiki/Semantic_Web

This is a really important point, because the worldwide web (www) was designed for openness, collaboration, and compatibility.

This is also the origin of ideas like XML, which were designed to have schemas, namespaces, and transformability.

A lot of principal ideas have been lost in the name of productivity or profitability. Which is undermining innovation, free data movement. Also, JavaScript also used to be a weapon in the browser wars for creating incompatibilities in browsers (see Internet Explorer).

So the saga is rather complex. But the conclusion is clear: if you care, insist on openness and compatibility on the web. And study the classics, the original design principles of the web, and their motivations.