In my experience AI reduces maintenance costs. Though, context might matter here, I'm working on a multi decade set of projects, while there is a lot of greenfield feature development, the old code / older projects have suddenly become a lot easier to work with, modernize, and in a bunch of cases, eliminated. Dependency on old libraries, build tools, in some cases updated, in other cases just eliminated, builds are f…
I have a very very opposite experience in a large company where everyone shits code all over parts of the codebase they don't understand with AI assistance.
We have had outages increase in tandem with lines of code shipped and outages are getting more and more severe. Yes we have improved much old code, deleted more old code, can automate code modernization, can better diagnose issues, have more options for mitigations, etc.
But all that has not offset the sheer magnitude of code being shipped which no one really understood.