I find it very aggravating. I’ve tried all the steps in articles on how to get messages and the unread message counter synched correctly, but still haven’t found the solution. I just conclude that it’s user error on my part, and end up powering down and powering up my phone and my watch twice every morning and manually clearing messages. When I’m out running errands and potentially expecting important messages from my loved ones, I don’t want my watch to say I have unread messages when I don’t.