IMO, outside of toy projects, all engineering and manufacturing nowadays is not only complicated but complex: the product may be dead simple, but the business and production processes are embedded in a complex system. Market, distribution, supply chain, people, and other forces conspire to make it so. No wonder that, when new resilience-oriented models are attempted at these companies in the place of traditional waterfall, they often overperform.

Also IMO, outside of toy projects, all contemporary software development is not only complex, but complicated. Which is one reason why almost all large software companies that attempt agile end up with something more like agilefall.