While people can be physically only in one location, they do get their information from a variety of source online. Comparing Google to a town square is dumb, when you account that Facebook has much more engaged users than YouTube.
At the time of writing I'm reading stuff on Facebook, Reuters, Yahoo Finance, Twitter, Reddit and watching YouTube videos in between.(HN as well) I'm present on all of those "squares" at the same time.
I would like to be wrong on this and that google do not have this kind of power.
They did. Maybe not in public, but it has been communicated clearly to the employees:
https://www.breitbart.com/tech/2018/09/12/leaked-video-googl...
I'm not saying this is okay--it probably could've been conducted in a more (politically) inclusive manner. But my argument is that this doesn't apply to the GP.
Edit. Also of course the main post about comment censoring is troubling.
For this analogy to be correct, there can be no equally populous squares. But there are equally populous squares.
So, no. One square dominates viewership (ie the town square <-> Google). You can switch to another square (ddg) if you want, but you don't get the viewership that you'd want to get the reach that you need.
It the same monopoly that a town center has in term of political activities. Anyone could easily choose to switch to hold demonstrations somewhere else, but the result of holding it where only 8% of people will see it will make that less of a choice for the ones organizing the event.
As a society where I live we recognize the benefit of political diversity, and we acknowledge that the disruption that such political activity bring is usually minor. As long it does not cause prolong and significant disruption to everything else then the benefit of giving everyone equal right to demonstrate in the town square is a benefit.
I do agree however that Browsers are more similar to regular monopolies worries. One company in control of the market will increase prices, decrease innovation and create perverse market incentives.