Regulatory changes in banks kept accelerating in the last 50Y and I see no reason this will stop. It is harder and harder for them to keep up. Reasons for this are:
* Banks still have very old codebases and changing anything is fear inducing for everyone (automated testing is a new things for a lot of teams)
* Banks control very little of their core software. They have a lot of vendors for the same thing. You will see multiple vendors delivering basically the same thing in different parts of the bank, and at the same time multiple versions of those vendor applications in diferent parts of the bank. Integrating this is a nightmare (it can take more than 1Y to move a tag in a XML).
* IT is still mostly used for marketing purposes in banks, it's not a way of doing things. The design/integration is mostly discussed/designed by functional people. They are great, but it does happen that they don't see the full implications of their choices till it is too late. Also, because this is a design 'from above' changing anything takes a lot longer. For any change you have to convince a lot more people till you get to the actual person that will have to do it.
* A lot more complicated management reasons. Nobody wants to take a hit on a new IT project, and few people have the IT & banking knowledge to move such a project (why would you? they pay is average). You cannot progress with just one of them. Places where these projects happen is mostly close to pricing/trading as those are seen as profit centers and the bank is more willing to fail a few times till it can build something decent. As you get closer to the guts of the bank things get more and more...problematic.
Edit:
I had to add this. Central banks are also bad at IT, they do not set an example worth following. I consider this the main reason why all our interactions with banks are less than ideal online.
What about the regulatory context?
I'm thinking of banks, for example.