I suspect, from an S Class point of view, the Prefacelift W221 was a decent successor to the W140, (the W220 was a reasonable car but lacked the presence and build quality for a range topper), but the facelift cars are definitely inferior in terms of fit and finish and equipment offered.
The W222 took off where the W220 left off and is basically a big C Class. Which works out well if you want a new C Class as it looks really classy compared to the old ones, but once you look past the glossy veneer of tat, they're pretty vapid. Like pretty much any premium brand.
Driving a 22 year old A Class home this morning put a smile on my face for it's stupid simplicity.
Bro's were all W222's I think (I have zero interest, so never looked that hard). But mid to late 20-teens era. Having bombed about in one of his soot chuckers was a baseline for the sort of car I wanted. First testdrive of the x351 variant of the XJ was enough to convince me - so much of a better car to drive, and a far better laid out interior, despite the frog eye vents (and don't get me started on it's pig ugly arse). It was also way more comfortable than his S Class at the time, though I think it was only his last that had the uprated seats.
But, I agree with you, MB seem to make each iteration even shitter than the one before, somehow. Which kinda proves my feelings that they are failing fast since the late 80s...
I agree with simply snotboxes. I sorta had a soft spot for the battlebus, which was shit in every way, but it was also fun. I actually really enjoy driving her car as well, as, although its a paltry claimed 163bhp, it's manual and on a fantastic chassis, and being a base model, has no shit to distract you. Last car I drove with such a fun drivers chassis as hers was a Alfa Guilia, modern one, not the classics.