If you’re good enough, your audience won’t care how dress. They’ll even consider it a sign of your excellence.
If your’re not that good (not a put down, just reality for most of us), you’ll have to dress up.
“how you dress”. Typo.
BTW, “what if they dress in their underwear” is stupid because they don’t. Supermodels, on the other hand, we don’t object to seeing in their normal work attire.