" Anything a human can do, a bot can do."
Dramatically reducing the number of bots is the goal, not perfection. Very expensive effort is required to defeat nominal bottraps. This has been shown widely. Captchas and 2FA are widely used because they largely work.
Also, there are things people do that bots can't. No one on Steemit, to my knowledge, has ever even tried to cut bots.
They're too profitable.
"1 vote = 1 vote means you'll have a massive Sybil attack on your hands."
Sure, if you leave bots in place. Sort of a self-fulfilling prophecy then. Given that ~30% of SP supports the witnesses, and that but 2/3 of the top 20 are needed to fork, that's not a great expense to just buy the VP to own the witnesses.
That's not a Sybil attack. It's a bargain.
What really matters to Steemit is rewards for content. Were the gaming that produces all the distortions through bots and curation rewards obviated, retention might crack 10%.
I bet it's getting worse, instead. I've read estimates as low as 8%. Those algos aren't gonna do a bit of good on a dead platform.
Either the Steem gets more broadly distributed, or nothing will fix retention.
Losing bots, egalitarian voting, or at worst a Huey Long style 3% -300% VP, and ending curation, would leave all the whales their mined stakes, and those stakes might become of lasting value on a platform that kept it's users posting and upvoting.
No one would benefit more from a rising Steem price. Nothing less is going to raise it in the long term.