The minute speculators stop buying Steem it may collapse because there is no business model or revenue source only the hope speculators will value a site attracting users and not use common sense.
The platform itself may not have ads, but the content itself can be ad-style / ad-supported even include gray-advertising. So, in that sense, purchasing steem power also gives you the power to commercialize products and services by reaching a broader audience.
True, whales provide advertising with their up votes. That is why Steemit circle jerk posts make more money because it help create demand for steemit and virality. Steemit success stories make more money for the same reason. Hot girls traveling while making money because they want to attract people that want to do the same (who doesn't want to travel the world for free). "Crypto celebrities" make more money because whales want influential mouthpieces.
Unfortunately, the kind of content I like to post and read about doesn't ever seem likely to make much money. I am starting to get why some people call it unfair. It is free money, so I am not really complaining, but my last posts have been at something like $0.50 a hour... at some point it is probably not worth it.