The MAX has a modern wing and the latest fuel efficient engines, it's a pity Boeing didn't bolt them onto a new fuselage instead of a relic from the 1950s first generation of jet transports.
If the MAX can't be recertified then the supply chain may have a hope with the C919 which has a large amount of US sourced content. If the Chinese ramp up production to fill the void then there will be considerable demand for engines, APUs, FMS etc to be filled, keeping American workers in jobs. Limiting the contagion from spreading much beyond Boeing itself and the factory towns which produce the MAX would be preferable to the ripple through effect where shops are forced to close because workers lose their jobs at factories which supply components to larger manufacturers in different states which in turn supply Boeing.
Even if some authorities accept a fix, the Chinese may demand substantial trade concessions in other areas in exchange for approving the aircraft. If these aren't forthcoming they could make any acceptance conditional on impossible terms such as a completely new flight control system or ban the aircraft all together.