Musicianship can certainly be entertaining, on it's own, but I'm guessing the OP was referring to the OMB approach, where the audience benefits from a little "nudge" from an EmmCee. Most large scale concerts are all about hype - there's pyrotechnics, extensive lighting, smoke, and video .... all that adds to the entertainment value, but (once again) if you're talking more serious listening environments (jazz, classical), the audience probably doesn't expect too much of a "showman."

I pride myself on being a showman, who's constantly trying to improve my musicianship. They go hand in hand, for me. I have some people fooled into thinking I can even play jazz, although, I won't dare put myself in that category. I have a jazz "feel", but lack serious, trained chops. There are nights when I desperately need to showcase some technique, if only for a song or two. Last night, for example, I played my tenor for 1/2 of the first set, and interspersed it throughout the night, whenever I could. It gave me a more "legit" element to an otherwise sterile (digital) performance. Even with all the improvements that modern keyboards offer, there's still something special about adding an acoustic element to a digital performance. (guitar, sax, even a tambourine helps make it sound more believable) I'll be tantalizing my crowds all month with guitar, bass, uke, mandolin, clarinet, sax, flute, and creative Manhattan Transfer-ish harmonies behind our many guest singers. I see my stage as a mini showcase each night, and the balance between music and schmaltz is adjusted as needed. Every night is different.

There is a great quote from the movie "LaLaLand" that addresses jazz, but it really applies to my performance approach, as well.
"... it's conflict, and compromise, and it's different every time. It's VERY exciting"
Now, I realize "real" jazz musicians rate this movie up there with Kenny G, and Jimmy Buffett, but I see something in it that will shine, if they ever take it to the stage. Gosling and Stone are charming, but give those songs to Sutton Foster and Jeremy Jordan, and they'll come alive. I can't wait to see if they adapt it for the Broadway stage.
But, I digress ... aw, hell. I'm done. You get the point. You need fluff AND fiber.