Where geographically are you basing that on? In another reply 6nf mentions Osko etc. on the New Payments Platform in Australia, which is fully settled in real-time, 24/7, but even before we had that our Bulk Electronic Clearing System (BECS) cleared and settled everything twice daily on business days and Real-Time Gross Settlement (RTGS) has existed for years for high-value domestic payments.

Cross-border payments have usually taken longer, but the point of my comment is that that is very quickly changing (and already has come a long way in just the last few years). So you may be thinking of older technology or places with less advanced banking systems than what a lot of countries have now?