Hello @ats-david, I hope you will read this comment. I completely agree with the fact that Steem is designed to only let money out of the system. And this will become unsustainable as soon as the system stops growing.
Ads are of course THE solution to this problem, and I must insist, the only solution. This is why I loved your post because it really forsees what will happen in the future.
However, I would like to add a twist. If we follow your model, then every stakeholder in steem will be exactly like a shareholder in Youtube, and we will fall in the exact same pitfalls with monetization that Youtube has. This is already better than the current system on steem, but I think we could do better.
I see two options in front of us:
1- We follow your model where people can choose whether they see ads or not. Obviously people need to be incentivized to watch ads. Now my proposition is that 50% of the total ad revenue generated by the Steem ecosystem will be split between the users that opt to watch ads. Only 50%. Here comes the twist: The other 50% will constitute the rewards pool on steem! Instead of creating new steem with every upvote and taking money out of the system through inflation, let's create the newly distributed steem tokens by paying for it with add revenues.
Now this brings me to the second option we have:
2- Let's just make adds mandatory to watch for everyone! This will obviously maximise add revenues for steem, and we won't need to pay back dividends to stake holders for watching ads.
Why is this good? Because now, we can just create a rewards pool out of this ad revenue. Every upvote on steemit will give money to the content creator and curator, and instead of having this money created through inflation, this money will simply come from ad revenues.
I think both systems are awesome because they allow the steem ecosystem to stay as it is, by which I mean that the content is rewarded by people upvoting and not by the total number of views.