The standard is the web platform itself. That's the only standard that will ever be followed to any meaningful degree.

Much of the needless splintering we see today can be traced back to having too many mutually-incompatible reactive rendering systems. If you make a button in React, even though I'd like the exact same button in my Vue app, I can't use it because it's rendered via a different API.

The core barrier here comes down to the different templated-rendering systems. What we need is a browser standard for templated/reactive rendering of DOM content (data + template = DOM). The <template> element doesn't count because it doesn't actually do anything. Web components are nearly useless without having a story for reactive rendering.

Beyond just compatibility this would give web apps a massive performance boost, in terms of both CPU cycles and initial payload size. It's long past due.