I depends on how much you like to walk with your bike. I carry a tube, patch kit and bacon. And a chainbreaker as part of a multi-tool. I decided to forgo the chainbreaker/multi-tool in my only race this year and had an awkward shift that broke my chain. Never again will I be depending on the charity of others to help me out if I can help it. Carry a tube anyway.
WTB tires/rims seat really well, but I've never had a combo that I could not get off with my thumbs.
Also, don't tighten your tubeless valve with pliers if you are not going to carry pliers to get it off. Learned that lesson the hard way.