In many countries, it is illegal for a company to unfairly exploit its dominance in one market to gain advantage in another market.
But Google aren't doing that.
The argument of these complaining companies boils down to "our business is so crappy and generic that we have no customer loyalty at all, and as such our customers simply click on whatever result comes first when they search". Therefore they argue "we should be first because otherwise it's not faaaaaaaair".
If the only justification for your existence is that hapless customers end up at your website due to an accident of ranking, why should anyone care about your business? Facebook, for most of its history, wasn't crawlable at all - the entire site was behind the login screen. Literally the only search term they showed up for was Facebook. Guess what - it didn't hurt them at all, because their customers wanted to go there.