I teach graduate and undergraduate courses in the humanities at a university in Japan. We don't know yet what will happen with our new school year, which begins in April, but some of the faculty have already started to experiment with online tools to see what might be feasible.
Each semester I teach a graduate seminar that typically has about a dozen students, all sitting around one table in a cramped room. The format is ideal for discussions, as we can all see and hear each other and read each other's expressions and gestures in real time. (Needless to say, the format also seems ideal for spreading coronavirus infections.)
If I had to, I could teach the seminar using Google Meet or a similar service, though it would be difficult to replicate the spontaneous interaction of the in-person discussions. However, there might be advantages to online discussions, such as allowing people more time to compose their thoughts before speaking or writing. I won't know until we try.
My bigger concern is with two freshman courses that I am scheduled to teach starting in April. While graduate students are already socialized to university life, first-year undergraduates are being exposed to it for the first time. I worry how well newly admitted students would be able to adjust to the university if they are still sitting at home by themselves in front of their computers. (Most students at our university live at home or in their own apartments, not in dormitories, so the housing issue is not so serious.)
Other commenters here have noted the difficulty of moving lab classes online. To those I would add foreign-language classes that emphasize spoken interaction and practicums in subjects like nursing, medicine, physical education, etc.