You are missing my point.

You said the following;

it means that all other upvoted posts earn more, and it also means all other voters have more influence in deciding on rewards based on their own individual preferences.

All other upvoted posts earn more? No. Not really. Definitely not enough worth mentioning. As you said, it is distributed according to current payout, so really the only people who benefit from it to any level of significance are the few top trending posts.

Speaking of the top trending post, it is your friend. A post that has concentrated whalevotes beyond belief, but I don't see your downvote on that one. And he benefited from you downvoting this post more than anyone else did, but surely that was not on your mind when you downvoted... Just a happy coincidence.

All other voters have more influence on deciding rewards? No. Not really. Definitely not for the 95% of voters who's upvote means absolutely nothing. Perhaps their vote might be able to add on a few cents to the trending posts... ie, your friend. But, to anyone else, their vote would have no effect.

So, no. Any time you downvote a post. You're not helping everyone. You are helping the top two or three trending posts. I should probably pay more attention to who is currently trending or heading there whenever you do downvote a post like this in future.