Many of them certainly benefit from lobbying the larger corporation. In any case, shareholders only invest in companies with an interesting ROI, that's what the figures show, and for the ROI to be interesting, the company must be doing well in its net results.

Monopoly happens in some segments, such as social media, but it's not the main factor for such “success”, since the general public is mediocre with its demands and the competitors are very bad. I write all this thinking mainly of Apple and its products.