Skilled players are normal people lmao, just shut up. Good players actually show a game better off than mashers, they do stuff and show what characters can really do so people can like a character more. Nobody likes gameplay of people who never played the game before and only help to promote the game but probably will never touch it again after.
There is value in showing both novice gameplay and high level gameplay.
In terms of broad appeal it is definitely better to have casuals and inexperienced players market your game because it makes it seem more approachable for newcomers. Take a look at some of the ads for games with very competitive and high level players like Smash, Halo, Call of Duty, and League of Legends. Most of these ads don't feature confusing ultra-high level gameplay or super intense players, but feature average to straight up bad casual players having a good time. It can be intimidating to try out a game you've never played before, and the last thing you would need is to be overwhelmed by confusing, unfamiliar gameplay. You don't want to gatekeep potential customers.
I do agree however that there should be more content of experienced players playing the game and showing off high level gameplay for the veterans. It shouldn't be the main marketing focus but they can't just forget about the existing fans