The problem is that Apple doesn't have anything close to a monopoly if you consider them a player in "PCs" or "Smartphones". It's only when you consider "Apple PCs" or "iPhones" as a separate market that it would be comparable to the MS situation.
There is no reason for me to use Apple products(Except when I need to hit Compile on my Javascript apps)
There is plenty of competition, its that Apple users want the government to fix Apple for them. Its easy, stop buying products that are anti-consumer.
The problem is more generically when some company use is its power (company size in a market as buyer or seller, technical possibility to block competitor, etc ...) to disable competition instead on fighting on quality and price of their product and services.
I believe that you can make this argument for Apple easier than you can make it for others because they make most of the product (i.e. hardware, OS, most of the services), but it's still a lot harder than looking at Microsoft with >90% market share of all PCs and agreeing that that's a monopoly.