Banks will not work like that for next 10 years at least. The tiny amount of money one could save on those big banking projects by using llms aggressively will bite back immediately when shit just doesn't work, clients leave for good and regulators will fine you to the ground (or remove your banking license). Many other businesses who are not race to the bottom and realize how crucial reliable IT is to their business also won't go that way anytime soon.
World is not ending, there is some transformation and thats about it. Its true there will be much less jobs for devs but its mostly affecting newcomers. Statistical models are not making code better than experienced humans, and won't for some time if ever.