The cognitive debt is by design. Now everyone must use an LLM to maintain the codebase, because it's beyond any single human's capacity for understanding.
Part of the problem is that of human alienation. By excluding humans in the construction process, it has taken away any skin-in-the-game for humans. So, there could be a point where some bugs become unresolvable because LLMs dont have an adequate causal model and fixes by trial-and-error wont work in cases where root-causes are not properly addressed - and the project gets abandoned as a result. Witness the C compiler in rust [1], what happened to that after the initial press releases ?
This has been the case with IDEs as well. The most productive programmers have always delivered despite the tools they are forced to use not because of them. The less productive programs fail to learn because they are handheld by tooling.
[1] https://github.com/anthropics/claudes-c-compiler