Does rev-matching create more engine braking power than just letting the synchros do their work? If not, what is it good for (other than reducing synchro wear)?

I'm becoming increasingly confused about this topic as I read more about it. Sure, I can rev-match and enjoy doing so, but am I kidding myself and not contributing anything to my driving performance?

EDIT: nobody brings up a good point. I'm also thinking that good rev-matching does the job faster than the synchros, so there are some tenths to be shaved employing the technique.