every time i hear criticism like this i have to notice that these problems exist mostly within heavily outdated american banking system. in my country i can send bank transfer to anyone within country for free and it will always clear within 24h, but less than ~3h if sent during normal working hours. transfers within bank are instant; when i pay my internet bill, for example, such instant transfer goes to payment processor (with little overhead ~0.3$). within EU, there are SEPA transfers

then, outside of banks in usual sense of this word, there is range of solutions from revolut to m-pesa