Why do banks refuse to clear transactions over a weekend? There's lots of problems with current payment infrastructure, but I'm not convinced that crypto would

Why do banks refuse to clear transactions over a weekend? There's lots of problems with current payment infrastructure, but I'm not convinced that crypto would solve them. For the thing in the OP though, some kind of crypto rail for these kinds of transactions probably would make a difference. The trouble is that Visa/MC don't just impose these restrictions for moral reasons, it's mostly because of higher charge-back rates and fraud.