The trick
I first figured this out for the most extreme case of tin can clingy food, tomato paste, but it works with most canned glop including soup: Use the can opener on both ends of the can. Gelatinous substances like soup usually just plop whole into the bowl under the influence of gravity, but if the material resists, you can push down on the cut tin disk at one end to push the stuff out the other. Zero waste, blood pressure unperturbed, life is good.