Earlier quoted context omitted.
Words get abused a lot, and for some of them, they do not have a clear-cut, universally agreed upon meaning. "Monopoly" is one of such words (others candidate include: freedom, democracy, justice). When random person X complains about, say, Google having a monopoly, there are two possibilities: - Person X means something along "Google has a dominant market position and abuses its power", slightly abusing the meaning…
I am the CMO for a company. Google is the ONLY ad provider that give results, all others don't even get any clicks. How that is not a monopoly on the classic definition? Every time Google has a bug and screw with my ads, the revenue of the company I work for tanks hard, and I am yet to find any solution for it.
It's true that if your looking at targeting users searching for something that it's basically just Google. But people are increasingly using apps and specific sites over general surfing. Reddit, tiktok, snap, etc. all have their own ads and collectively represent major competition.