In antitrust law, the key focus is on the excess profits companies can obtain from consumers through their monopolistic conduct. Profits is more important to that analysis than choice. Tech companies are in a state of monopolistic competition: https://en.wikipedia.org/wiki/Monopolistic_competition. There’s theoretical choices, but because tech companies have big moats, those choices are largely imaginary and the companies enjoy significant monopolistic pricing power. Telecommunications service, by contrast, is largely fungible. Even a small amount of competition is sufficient to curb the ability of providers to exert significant monopoly power to achieve excess profits.