Let's say your SP investment equates to a glass of water. The reward pool equates the the oceans of the world.

Well stated.

I'm only asking because people (especially the newbz) are getting obliterated with massive downvotes.

I've spoken to a few of the downvoters and their PRIMARY JUSTIFICATION is "protecting the reward-pool".

They charge that "low-effort-low-quality" posts "steal" from the reward-pool.

And they use that post-hoc-rationalization to downvote early and often.

Strangely, the biggest downvoter (steemcleaners) is also the most consistent TOP-EARNER.

https://steemit.com/distribution/@abh12345/an-attempt-to-show-improved-distribution-to-content-authors-over-the-past-year#@abh12345/q5jq67

It seems like their downvoting campaign kicks dust out of the hands of small accounts and back into the reward-pool, which then gets "re-distributed" to posts that "earn" $20 steem or more, with the lion's share going to the TOP-EARNERS (mostly whales and or their proxy accounts).

Anyway, that's my naive hypothesis, I was just trying to find someone who might know the actual numbers.

TL;DR, please consider the following question,

(IFF) the minimum payout was reduced to 0.001 and there was no downvoting at all, how much would that "cut-into" the "reward-pool-share" of the TOP-EARNERS?