> Does google really have the right to block my control over what is shown or not shown on my computer?
In general? Of course not.
On a webpage they serve to you? Of course they have the right to, to the extent JavaScript makes it possible. What possible legal basis could there be for them not to have that right? With limited exceptions, they have the right to do wherever they want with their webpage code. And there is no legal exception against blocking adblockers.
You didn't answer my hypothetical. Do they have the right to ensure that I am looking at their ads?
I don't see how they could, I can always look away. In that case, what is the effective difference between that and ad blockers that control what code/images run/display on my computer?
In general? Of course not.
On a webpage they serve to you? Of course they have the right to, to the extent JavaScript makes it possible. What possible legal basis could there be for them not to have that right? With limited exceptions, they have the right to do wherever they want with their webpage code. And there is no legal exception against blocking adblockers.