Good point, but yeah super small subset and a hefty, hefty fee. In terms of blanketed benefits afforded to only Deluxe guests, I can't think of anything else.
It isn't really a hefty, hefty fee. Or wasn't.
The Dining Plan used to cost $60/day for adults: 1 QS, 1TS, and 2 snacks/day, BEFORE it included alcohol.
Same time frame: Club Level was $130-$150/night. WDW's Club Level roughly =half-board, only slightly different. With 4people/room, that breaks down to roughly $35/night per person. At WDW prices, if you only bought breakfast, a beer, and a bag of chips in the QS, you could expect to pay about $35.
[For a long time though, the only way to book CL was to call. It was not well-advertised.]
In any event, CL = access to a semi-private lounge that serves food/beverages from 7am to 10pm:
7am-10am =continental breakfast buffet: unlimited beverages, cereal, pastries, bread, muffins, fresh fruit, yogurt, hard-boiled eggs.
Mid-day offers are very limited: snacks+ beverages
Evening offerings are a light buffet of appetizers and beverages (incl beer)
Then 8-10pm =desserts like the ones at Crystal Palace or Chef Mickey's
Non-dining plan, a food court breakfast might be: grape cup: $4.25, yogurt $3.40, pastry/muffin $4, juice $4, coffee $3.70= $20.
(A breakfast platter is about $14.85 +coffee $3.70= about $18.50.)
If you have a beer, expect to pay $8-$10 each. Breakfast, beer, chips = $35.
Current WDW pricing is another matter though. Current pricing is crazy. This year the CL add-on costs more like $250. I won't try to convince anyone that $250/day is a good price for CL at WDW.