A century ago, 3-wheeled cars were quite popular, like the Morgan below.
The sale of these cars has been banned later (until recently) in many places due to the associated safety concerns. There are many stories of these cars rolling over such as when turning around corners (for example, the first 10 seconds here and throughout). One source claims the 3-wheel system is actually beneficial as "narrow tires and a low center of gravity ensure grip runs out before lateral forces become a problem".
So the question is, why are 3-wheeled cars considered not effective or safe to drive while 4-wheeled cars are fine? What is the physics that makes this difference with 1 wheel? To me, it looks like lateral forces and banking have to do with this.