using it is not complicated. Understanding it is.
I'd say it is _much_ easier than understanding the modern international banking system which is the basis for pretty much all other payment systems today. Point is, you don't have to understand everything to use it. People don't ask how the banks manage their risks or validate transactions between them when someone uses a credit card.
They simply trust the system because it has worked for them in the past and because everybody else trusts the system.
If enough people trust bitcoin and work with it on a regular basis, newcomers won't even bother to ask how it works - they'll just use it.