As I've mentioned before, I think most discussions of simplicity are, well, major oversimplifications.
When people say the problem with certain systems is 'complexity' and that the solution is 'simplicity' what they really mean is actually specific sorts of complexity are the problem, and specific sorts of simplicity are the solution. I don't even think the issue is really best understood as a matter of of 'complexity' or 'simplicity', but that's another matter.
In 'Simplicity is Complicated', Avdi Grimm tries to tease out various different sorts of simplicity. He also talks about the tradeoffs that can be involved in each type.
These are the types he talks about
- Minimizing unnecessary effort.
- Hiding complexity.
- Avoiding difficult-to-understand features.
- Avoiding formal architecture.
- Elegance of design.
- Staying close to the domain.