So credit card is introduced after the great depression and just after WW2. Thus credit card system has not really been tested in bad situation (well, maybe little in housing crash 2008.) On the other hand, the same can be said about bitcoin, too.
No.
The credit card system is nothing but a first generation electronic money system.
It's already obsolete.
Just not as much obsolete as paper money.
Paper money is not obsolete, most people still use it when they go to the grocery stores, it is useful to have money outside of an electronic system
This is very different in different parts of the world.
Maybe we should call it "an accepted practice." Something could be functionally obsolete and continue for decades.
What I have seen in the US from the 1990s to today is a gradual decline in the use of cash, such that today even things like coffeeshop lines, where payments are 2-10USD, 90% are with credit cards today.
But yes in going to other countries I see in some a high use of cash. By the way it's not my opinion or assertion that using credit cards is better or more advanced, quite the opposite.