The opposite is actually true. If you are being slandered on yelp you cannot just choose for it to end. On the other hand you can use another search engine or advertising firm without any problems.

I'd refine that just a little. The users of Google are the advertisers. The people who search with Google are the product.

I'm not sure how this is relevant. As I said in the comment you are replying to, there are alternatives for both searching and advertising.

If Google removed my page from its results, or penalizes it, how do I get the same users to see my website again?

I mean, that’s what you’re saying. I can get the same users to see my site when they search for it without having to rely on Google.

That is not what I'm saying. I'm saying you can get users to see your site without having to rely on Google. There is no reason to expect that you would be able to get the same users.

I don’t get it: which search engines?

Bing, Yahoo, or Duck Duck Go.