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.
yes agree with you that because bitcoin needed internet connections and if Internet network paralyzed people usually will find another solutions to still make transaction and cash will be good solution for this problem and cash also will became the main payment in the world instead of bitcoin if this is happened