[jurassic]

Public speaking is certainly expected. Accommodations might be possible for somebody with an obvious and documented disability like muteness, but most people just experience different levels of anxiety which is considered "normal" and something you have to get over. You have to realize the PhD isn't useful on its own; it's just an entry ticket to a community where you will be in continuous collaboration / idea exchange for decades. Really difficult to do that successfully if you have crippling anxiety. It's just not the right fit for everybody.

Full disclosure: I also quit my PhD, for different reasons.