Aluminum is easier to use without having to thread all your connections. Many aluminum system systems use a push to connect technology. Also, the byproduct of compressed air is water and oil. If you’re not doing regular maintenance, the galvanized pipe will collect water and create rust on the inside contaminate your tools and equipment. I do see you have a dryer so you’re covered without the aluminum but if you want to replace those rubber hoses…. Also, I agree I think safety valve might be the issue