Yahoo has already been a de facto search engine in the mid-1990s before being downgraded by Google who was giving better and faster results.
Yes, even a giant like Google can be easily replaced
This seems unlikely at first glance when one thinks of Google's current dominance over the Internet but it is a reality that Larry Page, co-founder of Google, takes very seriously with good reason. Bruce R. Miller, software engineer at Google, said recently:
That wouldn't take much to allow a giant such as Apple, Mozilla or Microsoft to exclude Google and replace it with another search engine such as Bing. ― Bruce R. Miller
This is the main reason why Google constantly uses massive human and technological resources to avoid being downgraded in turn and so taste its own medicine.
Why Google Chrome and Android are so popular?
This is one of the many reasons why Google has developed the Chrome browser in order to prevent other browsers developed by potential competitors from blocking Google. And this is also why Google has faced the challenge of developing a major phone operating system, Android, to avoid de facto exclusion from this ever-growing market.
Google spends a lot of time with open standards committees to avoid that better exclusive solutions dominate the Internet market. Moreover, at any time, the Trump government could seriously damage Google or any other company that seems ungrateful to him.
Google is a model for all entrepreneurs
Like Larry Page, as an entrepreneur, even if we do not make millions like him, we must never take anything for granted and work constantly to improve our knowledge and promotional tools to make the most out of the Internet and Make it a tool that helps us develop our business and maintain jobs that help honest workers support their families and loved ones.