The FE should have never been eliminated. A person with deeper technical knowledge of the systems and not concerned with flying the plane in an emergency would be very beneficial in emergency situations. (If he would have known about MCAS that is)
When the FE was eliminated on new airliner designs some 40-50 years ago, then it was a conequense of a shift in design philosophy. A change from manual failure monitoring to failure tolerant systems.
The 737 was designed during that period as an "improvement" of former old philosophy designs, 707 and 727. Some systems were made failure tolerant, some not so much when they were not considered really critical or potentially catastrophic in failure mode. Also because they had proved rather reliable on 707 and 727. One such thing was AoA detection.
Then on the MAX, with the MCAS, a potentially catastrophic band aid was added, taking input from a single AoA sensor.
It is old knowledge that failure tolerance on sensing in its simplest form means three sensors and reading two which match. There are other more complicated ways to gain the same or even better failure tolerance, but the MAX hasn't taken advantage of any of that yet. That is unique among all large airliners being produced in the 21st century.
That will be corrected, either by a software update which removes the catatrophic potential, or by a more radical modification making the MAX on par with modern airliner design philosophy.
It is quite sickening to see on this forum how posters, who claim to be 737 pilots, claim that this issue is solely a training issue, and how superior pilots will always avoid CMAS related catastrophe.
Being an occational airline passenger, me (and my wallet) are alone to keep the airlines in the air. I do not want superior pilots to be the only thing which saves me from catastrophe. When I order a ticket, then the web site does not offer that I tick a small square telling "superior pilots only". I have to take what is available, superior, average, or below average pilots. And BTW, all of us, including superior pilots, got a birth certificate reading "zero hours". Superior pilots become superior by polishing their skills as non-superior pilots.
This grounding is likely unique in the world history due to the large number of "stakeholders": Boeing, FAA, EASA, Canadian CAA (plus others), DOT, DOJ, FBI, and even the US president has involved himself. Did I forget some?
I think I did. One which we haven't head about, and probably never will hear about: Insurance companies.
Insurance companies sell insurances for one single reason, to earn money. No MAX will fly again until all former mentioned stakeholders have convinced them that the red flag can be removed from the MAX. Superior pilots or not. Normally insurance companies around the world would side with the FAA, but since nobody else seems to do so today, then it is likely more complicated this time. This event could turn out to become a lot more "politically toxic" than earlier events such as Comet, DC-10, 787.