Meetings should be 30 minutes by default unless there are circumstances that warrant more time. A lot can be done in 30 minutes. That's one thing I agree with Google people on, but then again, people added so many random meetings on calendars without even asking first.
@timnitGebru
I sometimes think it depends how many people are in the meeting. I have a team of 7. We meet weekly and there is always a lot to discuss. So it's always an hour.
On the other hand, I have an extremely verbose boss and sometimes a 30 min 1-on-1 meeting with him barely covers one topic on the list.