Regardless, had Commodore not bought it Amiga would have simply soldiered on seeking more investors and a potential buyout, or gone under because of the bad financial state they were in and its assets split up among the investors.
With Amiga not being able to meet their payroll obligations or repay Atari the money they had borrowed, there was no way they could soldier on.
Without commodore the Amiga would have ended up being controlled by Atari, with (IMHO) even more disasterous results than what happened under commodore.
While commodore could have done better, Atari could easily have done worse. Either way, by 1993, neither of them could survive against the PC market.