Delta has had a well deserved reputation for offering members very little award availability, at least at any reasonable price (the ‘saver’ level). It’s hardly a new phenomenon.
Occasionally though award space at the low saver level on Delta’s flights open wide up. Right now you can use SkyMiles to take the family in business class to Europe for summer travel. You’ll find wide open availability most days for several seats on an assortment of routes this summer.