I think we need a better term than monopoly, that separates it from what people usually mean which is 'the best product'. I literally cannot think of any sort of product or service with lower switching costs than internet search. Typing bing.com takes 0.8 seconds and costs $0. Hundreds of orders of magnitude easier than switching to a different railroad if only one goes through your town. Google is a big ass company…
From a consumer perspective it's not about being able to switch search engine. Google is potentially putting a drag on entire economies, both money wise, and innovation wise. If every service you use has to spend extra because Google has an advertising monopoly then every service is passing a cost to you. If every service needs to do it the one way then there's no advancement, no new models, just "give Google money" forever.