They are convenient–those cooking sprays which come in flavors, in various formulations (olive oil, canola oil, lecithin) and which promise no sticking food.
Problem is, when they are sprayed directly on nonstick surfaces and heated, they can turn gummy, gradually building up and destroying the release properties of the nonstick coating on the pan.
A better idea is to spray the food with the spray and not the pan. Some recipes will indicate that instruction and its a good idea.
Admit it, most people don’t really “wash” their nonstick. A swipe with a wet sponge is usually enough to pass the “eye” test. But gummy nonstick sprays aren’t easily visible on dark nonstick coatings. The result is a gradual build-up of layers of the spray that eventually turn sticky and turn the nonstick pan into a “sticker”.
The sprays are really fine for use with stainless steel and other not-nonstick coated cookware, but use them only with caution with nonstick cookware and bakeware.