ZIP: Reduce default Shielded Transaction fee to 1000 zats

Standard 1000 zat tx fee is now implemented across the top wallets. Correct, blocks are no where close to filling up and we have a 40 block mempool limit which can accommodate 3-4 million transactions which the Zcash big close will chomp through every 90 seconds or so. Can Zcash scale to a million users?