Also for adults, it's a much less intrusive technology.
Whereas on a phone, the temptation to open apps to do things is always there.
It's almost like comparing an eink device with a regular tablet.
Also, almost every smart watch allows you to block notifications on top of what you phone already blocks, so if you have apps that you want notifications from for when your attention is on your phone, but not all the time, you can only allow those through. It's not "anything it wants", it's anything you choose.