The reason why I prefer to hold interviews and hiring events in person is because the panel is focusing on one thing only and that's choosing the best candidate.
The tendency to have multiple applications open at one time and reading emails and messages that pop out on the screen whilst sitting on the panel causes distraction and simply wastes everybody's time.
The panel made preparations for the interview, read the candidates' backgrounds and prepared questions. The candidates (hopefully) also made time to prepare, let's show a little respect for each other's time and be actually present in the moment when interviewing. When interviewing online, the do not disturb function is absolutely essential.
The panel has to ask questions, make notes, interact with the candidates answers and create a desirable environment for the candidate...I dare to say that's enough multitasking in one meeting.