And most importantly, given that most banks are still using absurdly antiquated software, any new systems they develop have to be carefully designed for backwards compatibility.
Things move so quickly that one year in crypto is like 7 years for any other industry.
In an open source crypto environment where new innovations are pulled off rather quickly through collaboration and transparency for the greater good of the community, the banks are going to have a hard time innovating themselves, catching up. Banks/governments do know they simply can't shut down Bitcoin/cryptos, staying competitive is the only option.