Google search became a near monopoly because the other search engines can't compare. When it first launched, it was far superior to the competition at the time (Altavista, Yahoo, Excite, Lycos, Ask Jeeves, etc..) To this day Google search is far superior IMO to the other search engines that exist (Bing, DuckDuckGo, Yandex, etc..). People use Google search because it gives better search results. I personally couldn't care less what default search engine is set in a brower or device; I always changed it to Google if it allowed me to, or ignored the built in search engine and go straight to google if it doesn't permit me to change the default search engine. It just works better IMO.