Why are they a monopoly in this sector? What's stopping people from just switching to Bing if their product goes to shit? Doing that literally takes like two seconds
The cost of starting a competitive search engine is incredibly high, and unlikely to get real funding as a) the business model would likely have to be subscription based to align users interests long term with the companies interests, this alone is probably enough to make it a pass for most VCs, b) the incumbents in this space have an immoral amount of cash to spend on either acquiring, bankrupting or destroying any meaningful competition.