Historically, in EU the private industry chose not to solve the problem because (just like in USA) the problem is profitable for them. Sometimes people need fast payments and you can charge them lots of money for that; if everyone's basic payments are fast and cheap, then you lose that revenue.

The point of change in EU was legally mandated changes (PSD) which (after a transition period, something like 2 years maybe?) essentially required banks to deliver payments within a certain time or compensate the payer for any losses/costs caused by the delay, at which point suddenly the private industry managed to quickly solve all the technical and organizational problems that were impossible before.