inputmode attribute

Hello

I am trying to figure out the story of the inputmode attribute for the
<input> element.
I'm seeing discussions about that attribute long back (5-10 years), and
based on https://caniuse.com/#feat=input-inputmode, it was supported back
in firefox 17-20.

But what happened to it? Why are no browsers adopting it? Giving hints to
mobile platforms about which keyboardtype to use seams very powerful. Using
type=number sets a lot of other limitations on the field.

The best way would be to set hints like this using css.

Is there a work in progress here?
Is, and will it be type=inputmode that is the way to do this, including
it's limitations?
Will there be a bigger standard for controlling things like this on mobile
devices, as it becomes more popular?

Best regards
  Lars