Banks would use blockchain because it is more affordable and also it can expand the number of its users because those people who are using blockchain will try banks that use blockchain too. Blockchain is much cheaper than the traditional system and it also offers fast transaction, So i think banks should use blockchain as soon as possible.
It's not so easy. There are two different things:
- Banks would use blockchain, because it will be faster and cheaper: Yes, it's blockchain, not Bitcoin
- People are using blockchain: Yes, because people use Bitcoin which is blockchain too
- People will search for banks who have implemented the blockchain technology: No, because people won't mind what's behind the scenes in banks' system, is it a blockchain or not, they only want cheap and quick service, and they don't care about how banks solves this inside their systems. If banks can solve it with blockchain or without blockchain, people usually don't care
- Banks should use blockchain as soon as possible: Yes, because they can cut their costs on international transfers (with blockchain and not with bitcoin). National transfers and intra-bank transfers are quick and cheap without blockchain, so banks won't develop this. International transfers are mainly used by companies (most of the people start international transfers really rarely, few times a year). People won't choose a bank depending on the usage of the blockchain for international transfers, because this is not their main interest. It's only companies (export-import companies) who can benefit from switching to blockchain, but really big companies has discounted fees at banks, so it's only the time that can be the real benefit for them (nowdays international transfer takes 2-3 days, with blockchain, it could be some hours, but in this case all the banks should use the same blockchain system)