When they saw Bitcoin and Ethereum they obviously understood a great disruption was coming and acted on it. SWIFT too.

A Central Bank do not share everything they consider/plan with the public. It is not really hidden or secret, but they also do not make a press release about it.

Also if they are fundamentally gonna transform our banking system they better start early because a lot of things can go wrong. I estimate the time to build such a system is about 10 years if everything goes well.

I do not know exactly what went wrong, my guess is the banks pushed back as much as they could because most of them would have been made irrelevant under that model. Now they are talking about Ethereum and Solana because they understood they have to fight against the Dollar in this arena.