MCAS in itself doesn't seem to have been the problem. The fact that MCAS relied on a single sensor (no idea how that got certified in the first place) and that pilot were not aware of MCAS and how it worked were the problems. The latter was due to Boeing trying to avoid re-training and re-certification of air crew.
> pilot were not aware of MCAS and how it worked were the problems
If the pilots followed runaway trim procedure, which is how the MCAS failure manifested, they would have been fine. In fact, that's what the other unmentioned crew of a 737MAX did that survived MCAS malfunction and landed without incident.
Boeing issued an Emergency Airworthiness Directive about the procedure, which the Egyptian Air pilots didn't follow, either.
