With engines ranging from civilian turbo props and turbo fans, to military fighters and helicopters, to rocket engines.
Are the insurance premiums the same? I don’t know, but I’d be surprised if that’s the case today after all the design and construction problems on the Boeings.
Edit: for this not familiar with Baseball analogies: https://en.m.wikipedia.org/wiki/Brushback_pitch
Yes, they still have a long way to go, but the C919 is flying and hasn't crashed yet.
Building a passenger jet isn't even that difficult. The difficult part is making it economical - low weight, fuel consumption, high reliability, parts availability, service/repair centers, training facilities, trained crews ...