What do you think would be the consequences if suddenly all governments disappeared and countries had to function without central authorities?

One of the options that seems more likely to me.Legal, economic regulations, etc., known norms and rules of social functioning would disappear. Probably a huge chaos, universal panic and crime on an unprecedented scale would prevail. In the face of crisis, smaller and larger communities sticking together would start to emerge their leaders / leaders in order to ensure the group's safety and protect its interests. Those that function better would probably become prototypes for others. This is probably how a new order would start to take shape, or on the contrary, a return to the old, only in a worse execution.

We complain about the authorities, but without them everyone would want to rule on their own and there would be nothing but great chaos.

Look, Haiti is a good example.

Governments may come and go, but there will always be a group holding onto power that will "adapt"!

There will always be a leader

Swiss people manage somehow, so we (as Poles) would also figure something out. There is always the local government left, which would have to take over the duties of the central government for a fee.