The key point. SW online does not have the charachteristics of natural monopoly. I have 8x choices in my integrated search bar (the default ones on Firefox). There are some network effects, or returns to scale from usage analytics that impact quality, but that is a different animal. MS Dos / Intel x86 technical architecture was actually exclusive.

Also, with MSFT was clearly a case of prediatory pricing funded by cross-subsidy from the monoply business. They set out to 'kill' netscape in its infacy as a business stratgy. Google is arguably just doing its job, and doing it better. Advertisers fell like there is "no choice" (because of scale), but they are sock-puppets. The consumer is the searcher. Advertisers have plenty of other places to advertsise online, so there is no monopoly.