Can a SpaceX Crew Dragon launch from a non-SpaceX rocket? If NASA decides to diversify, can they buy a Crew Dragon and stick it on an Atlas V or Delta IV? It

Can a SpaceX Crew Dragon launch from a non-SpaceX rocket? If NASA decides to diversify, can they buy a Crew Dragon and stick it on an Atlas V or Delta IV? It seems not. The Wikipedia page for Crew Dragon says "The spacecraft launches atop a Falcon 9 Block 5 rocket and returns to Earth via an ocean splashdown." [1] The Wikipedia page for Boeing Starliner says "It is designed to be compatible with four launch vehicles: Atlas V, Delta IV, Falcon 9, and Vulcan." [2] [1] https://en.wikipedia.org/wiki/Dragon_2#Design https://en.wikipedia.org/wiki/Dragon_2#Design [2] https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner https://en.wikipedia.org/wiki/Boeing_CST-100_Starliner