My vision for Steem is that it one day becomes a household name - that it’s something that everyone will see on whatever application they happen to be using. I see it being commonplace to see the words “Powered by Steem"

Ok. Why?

If there is a website... Due to rules of economy it will either thrive *(if it's good), or it will dissapear (if it is not good enough). Darvinian selection.

What is the place that Steem will/ should/ could cover?

Let's see a project that supports Steem: https://www.bescouted.com
How much those authors earn? Less than 1$.
Would you hussle to make changes to your website and use some confusing stuff like Steem for a dollar?
Would you spend a week, coding some extras in order to get a dollar?

No. 7 billion people don't need it.
7 billion people have no clue how to use it.
7 billion people have have no idea for what it will be used.

Try to explain them in simple words: you get paid by likes, likes paged on nothing, we just print them.

If at least you have provided a simple solutions to sign-up and to just copy-paste a short piece of code, it might work.

For some strange reason, you decided not to do that for 3 years.
I don't know why.