...As for the Concierge Lounge food certainly appears to have been cut back, and should not be considered a replacement for dinner.
Was it ever?
Some properties will put out a nicer spread than others, and occasionally you could sometimes make a light meal (especially if you are on a high-fat, high-carb diet
) from the offerings, but those were rare.
To the OP's point:
In the 20+ years I have been an Honored Guest/Marriott Rewards member (just made Lifetime Platinum ^), I have seen a tremendous improvement in the FS properties. The "bedding wars" of about 3 years ago was probably the most recent bump. Individual Marriott properties may decline, but if it gets too bad, you are probably looking at that city's soon-to-be next Sheraton or Wyndham
.