Smart watches are like tablets. The people who wanted one bought one when they came out. But now they have one and it works fine.
Adding new baubles might convince a few new people to buy one. And there are always people who will always run out to the Apple Store to stand in line for the latest iGadget. (Or whatever brand they prefer, if Apple isn't their game.) But that isn't most technology users.
There are two types of smartwatch companies: The ones who saw that the initial demand will wear off and are playing the long game, and the ones who wanted to make a quick buck cashing in on an new market that will drop the entire product line when the going gets tough. Which companies are which is left as an exercise to the buyer.