In what way has agile development contributed to complexity? In my experience it's been quite the opposite: Agile has led to better focused features that solve real problems faced by the customers, while minimizing waste, finally making a dent in Essential complexity.

Unfortunately, there has been a parallel explosion in Accidental complexity (over-complicated architectures, cargo-cults, crazy-complex auth frameworks...).

I'm beginning to wonder if developers (especially consultants, as others have mentioned here) are trading one form of complexity for another in order to keep their billable hours up, or improve their job security. Cloud vendors also seem to be contributing to the problem as well.