There is no value in Steemit besides money that can be extracted from "work". So yes it is directly comparable to online surveys. Steemit really isn't comparable to traditional social media such as Reddit and Facebook. Where the value of those sites from the user's perspectives is in general not monetary at all.

Vote quantities may get more balanced, but certainly not vote rewards.

Simply because it's not economically viable for the majority of people to amass enough SP to become influential. So a few new whales, and the present whales will monopolize upvote disbursements.

Even if Steem price surges, that won't affect SBD much. So it'll be locked in SP - i.e. illiquid.

In such a world, you would need an insane price surge and constant power downs for Steemit post rewards to be significant enough that you would earn more than through PPC blogging, or other online work.