what if someday when bitcoin has become the main payment instruments in the world. and how when the Internet network paralyzed. it means that we all can not perform various financial transactions? , is there any solution ?
Use cash.
when people have only a bitcoin, and they do not save real money. while they have to pay a lot of bills and utilities. this is what must be our consideration in the future. there must be a balance between bitcoin ownership and real money. probably around 50:50 to make us comfortable in living their daily lives.