I think all Airbus planes are fly by wire, but these not. Boeing have always kept a mechanical connection twixt pilot and surfaces. The problem her was that the manual effort on the pilot-operated control surfaces on the wings is simply not enough to defeat the much larger tail surface which remains in the hands of the MCAS system, even when at fault.
The Ethiopian plane had the pilots trying with all their might, but even with the tail powered down and not actively opposing them, they still had no means at their disposal to defeat the enormous tail forcing them to dive.
As usual with these things there are a lot of contributory factors, the problem is that most of them (in this case) lie at Boeing's door.
It seems that the only exception is the FAA's lamentable lack of true oversight into the design compromises and software fudges that they should have used.
I think the FAA is also in danger of losing its status over this affair, with some non-US Aviation authorities possibly intent on testing every Boeing new design, rather than taking the FAA's word for their air worthiness.