There’s several kinds of “quick release” bags. Panniers are often held down to the rack with a spring or bungee on the bottom and hooks on top. Rivendell has something for large saddlebags that used a hub skewer. A handlebar bag can use a decaleur. Topeak sells a rack and bag system called MTX where the bag slides in and latches, and some of the bags are large... the one that came with my trike is a top bag whose sides unfold to panniers. And one of the racks is a seat post cantilever type that comes off with one pinch bolt.

Undoing a frame triangle bag isn’t that quick - it’s eight or ten 2” Velcro straps. But it does have the advantage of needing no rack.