MCAS, again, is not a stall prevention device, it is a handling modifier. It makes the nose feel heavier to the pilot. Catastrophically so if activated improperly.
It is or claimed to be needed by Boeing flight engineers to prevent a lighter than desired stick force at higher AOA's.
The jet is designed to feel nose heavy at high AOA, the MAX engines being further forward in CG, act to increase nose up moments at higher AOA, not because of thrust, because of the aerodynamics of the motors being further forward. This lighter nose feel was not desired by the engineers, so MCAS was developed, or so I have read. Of note I believe in the two years the MAX has flown, the MCAS has never activated. Except for two accidents, erroneously.