No. I would be more worried about someone stealing my phone/watch and also having my credit card as well.
I have not had anyone try to pay that way. But I hope they will not have an issue went I insist on ID. We ID every customer who pays with a card. It protects both the customer and my business.
Cash is always king. It kind depresses me with my younger relatives who think cash is silly and don't understand why O try and convince them.to use it over cards. You can't bargain with a card for one. They actually get angry when they see a cash payment discount and think its them being ripped off for using a card. They don't get the legit reasons why cash gets favor.
Nope. I don't have a "smart watch" - because the only thing I use on my "smart phone" is texting, and rarely the camera.
I don't know what research you did ... but can't believe it's any safer than using credit cards. Either way, a databreach is going to cause problems. Same if you have your phone or credit card stolen. And it's easier to hack a cell phone, than a credit card. At least with credit cards, you can check the machine to see if there's a scanner attached.
I have no need and do not believe using said functions. Just another way to get you to spend more and give up a lot of personal info. Cash is king when necessary I do use a credit card.