Speaking is not the only means of communication, and I'd be surprised to find out that Biden doesn't rely on email and memo communication behind closed doors to make his job easier.

Thinking about it more I'd have probably still have been surprised at most points in his career. Not slipping back into stutter is something that requires a lot more focus than a politician really gets to commit to it at all times. Could be that Joe became mr. compromise because helping people get along lowers the amount of times he has to leave a conversation to reset his voice and get his focus back.

Having recently been committed to bedrest I know what it's like to get creative with your personal work environment in order to compensate for what you're not able to do right now.

It's embarrassing even when everyone around you is as supportive and non judgemental as they can be, for a president, I could see the history books recording this as an echo of Roosevelt's efforts to hide just how far his polio had actually progressed from the press. Even if not for ableist questioning of his legitimacy and ability to do the job, there's still the personal embarrassment of having everyone know your chronic medical struggles and even picturing what your worst days must be like.