I think the answer to that question is help who?
Each activity we do helps the entire ecosystem...even if you dont have much VP, an upvote does help. Plus, what you look at minimal in terms of a VP value, a new person might not.
70 cents isnt much compared to the whale who has a vote worth $100 but it is a ton for the person who has a vote worth a penny.
We all can help wherever we are. Comments arent dependent upon SP but they help. A VP to a new person, even without great value adds to their till. We never know what will motivate others.