If only simplicity always meant easy to use. There would be no paradox if it did.

One big problem is that for any product/feature not used in isolation in a very controlled context, simplicity is often suboptimal, inflexible and limiting.

Complexity is often the result of building one thing that works well in a variety of situations, a lot of interoperable things or features to work (relatively) well together, or one thing with a lot of ways to interface with it. The worst case is all three - which is true for a lot of software.

The result is a simpler purchasing choice, buy the most flexible product, but at the cost of far more product complexity than any particular user needs.