The other commenter pointing out that not all cans are recycled is part of it, but the other part is that many metals can't be reused as-is and maintain alloy c

The other commenter pointing out that not all cans are recycled is part of it, but the other part is that many metals can't be reused as-is and maintain alloy correctly. For instance, if you want to cast aluminum, you don't want melted down cans because those are intended to be stamped and are made from an alloy optimized for that. You would be better off to use some melted down cast aluminum so that it has the right additives for casting, but there are still subtleties in the broader category relating to casting pressure/temperature/etc. So, you might not want 100% recycled material, but rather 70% recycled and purified and then 30% of the right things to get the alloy you want with the properties you want. So, it's probably <100% and >70% of cans getting recycled combined with you want to only use so much recycled material for this application and the rest gets recycled somewhere else.