But the fact remains that you can disconnect everything on a B737 and it will still fly.
GG and LS you are talking about an analogue only aircraft. I have flown a 737 in full manual reversion and it was a non-event. What you are not considering is that MCAS is a digital system that applies a control input independent of the pilots. Pilots who were not told about the existence of the system or the full failure modes of it. To just dump it on the crew does not explain why the thing has been grounded and even then they have found other issues with MCAS. LS Airbus have included the" fly the aircraft" in their Golden Rules since they introduced FBW so the A350 is nothing special in that regard. Interestingly the A330 was not grounded after a legacy carrier crew put one into a stall and killed all on board and the A320 was not grounded after the Air Asia fatal accident off Surabaya. So there must be a lot more going on than you are willing to acknowledge. Boeing through their shortcuts and corporate greed have presented a product to market that has killed over 300 people. Therein lies the issue.