Are they? Or are they just not willing to put in the resources to fight to get a bigger share?

It’s been more than long enough that I suspect no one could launch a third phone. If it doesn’t have iOS or Android it probably just won’t fly.

So I’m not sure how much they have to worry about.

I can think of one company that could launch a phone with some success, if they wanted to. Nintendo.

Nintendo Switchphone2 - it is a Switch that can make phone calls.

Microsoft could do it if they wanted to, and didn't bungle it like the last three times. (lol)

The key in my mind is to NOT compete for the high-end, but as a feature phone.