Microsoft got hit with anti-trust enforcement for doing a small fraction of what Apple does. Both political parties in the U.S. seem to have abandoned anti-trust regulation in the past 20 years.
Microsoft got hit because it had, what, >90% of the desktop PC market? And that at the time where the mobile market was so niche (Palm etc) that it could be disregarded.
Apple is hovering around 50% of the market. It's certainly market-dominant, but by the standards of the 90s and the Microsoft anti-trust case, it's nowhere even close. By the pre-Bork standards, that's a very different story. Here's how we used to run things:
"The District Court found that the merger would increase concentration in the shoe industry, both in manufacturing and retailing, eliminate one of the corporations as a substantial competitor in the retail field, and establish a manufacturer-retailer relationship which would deprive all but the top firms in the industry of a fair opportunity to compete, and that, therefore, it probably would result in a further substantial lessening of competition and an increased tendency toward monopoly. ... The District Court was correct in concluding that this merger may tend to lessen competition substantially ... The judgment is affirmed."
And how much market share did the two companies in question have?
"... the combined share of Brown and Kinney sales of women's shoes (by unit volume) exceeded 20%. In 31 cities -- some the same as those used in measuring the effect of the merger in the women's line -- the combined share of children's shoes sales exceeded 20%; in 6 cities, their share exceeded 40%. In Dodge City, Kansas, their combined share of the market for women's shoes was over 57%; their share of the children's shoe market in that city was 49%. In the 7 cities in which Brown's and Kinney's combined shares of the market for women's shoes were greatest (ranging from 33% to 57%), each of the parties alone, prior to the merger, had captured substantial portions of those markets (ranging from 13% to 34%); the merger intensified this existing concentration. In 118 separate cities, the combined shares of the market of Brown and Kinney in the sale of one of the relevant lines of commerce exceeded 5%. In 47 cities, their share exceeded 5% in all three lines."
