A sibling comment pointed out that you're wrong about the Microsoft case. You're also seemingly under informed about monopolies. One of the core issues in the Microsoft case was that they're a
horizontal monopoly. Microsoft's monopoly affects all players in the market because a majority of the players use Microsoft's OS. They used that leverage against Netscape and many other companies.
Apple on the other hand has a vertical monopoly, they control the whole stack from hardware to software. While their influence on iPhones is absolute, they don't have outsize influence on other phone vendors. Also while popular iPhones don't have a majority of really any phone market.
Antitrust considerations are different for different monopoly types. Unless a company with a vertical monopoly also had a market monopoly position and used that position to actively influence/harm other companies it's really hard to legally pursue them. You can't fault a company for building their own products and trying to make money from selling them. If a Samsung washing machine has some cool feature when paired with a Samsung dryer, just because Samsung has a monopoly on Samsung appliances doesn't mean they're violating some antitrust laws.
If anything Google is in bigger danger of antitrust suits since they have a more horizontal position in the phone market. While they have token entries in the hardware market they're an OS and service provider. Which is likely why they're supportive is sideloading and alternate app stores, if they behaved like Apple but with a horizontal monopoly the DoJ would be all over them.