Ask a biologist or ML enthusiast; complexity is the natural outcome of a period of mutation/selection. It's a mistake to criticise the result on the grounds of said complexity, I think - rather ask what environment the complexity evolved to "survive" in.

It's boring common sense but don't take a bromeliad into the desert.

My belief is that all codebases that live long enough will develop this level of complexity with time. The only exceptions imo are where the codebase solves a very particular, fixed problem, e.g. a library for A* pathfinding or whatever. But maybe not even then.