Is their engine uniquely different from the rptor?
I am not familiar with the differences
Yes - competition is good. But after a while everyone can settle on the best mousetrap, and not spend tons of money for minimal gain.
Yes, it is not as good.
It is my understanding that the Raptor and other SpaceX designs are the most efficient and highest thrust producing rocket engines in existence currently.
I don't think anyone else comes close to SpaceX designs in terms of efficiency or thrust produced for a given size.