While the MAX was a knee-jerk reaction to the neo, the NG was a reaction to the 320 in the first place.
At that point Boeing was going for a clean sheet aircraft, then the 320 forced the NG ($2 Billion vs $15 Billion)
If the Cl to NG redesign would have included taller landing gear, we might not be discussing this. The NG was all good, except for engine clearance, that has haunted them, and now...it is a nightmare.
the $2 Billion they saved by not redesigning the landing gear/wingbox was gone in the first 2 weeks of the grounding...great decision.
Still no clean sheet ac.