I doubt an artist is only as good as their canvas, have you ever seen celebrities without makeup? The job and role of makeup and makeup artists is to improve appearance, if it doesn’t than, you can go without or find something else.
I have experimented with different makeup in general and it can improve my looks from no difference to pretty, same with makeup artists, I’ve had some makeup artist make me look like a clown to quite striking.
I’m not trying to say the makeup artists that I went to suck, because they definitely don’t, each of them have their strengths and weakenesses which I have tried to list, I don’t know why this is so hard for everyone to swallow.