Apple has a monopoly on the DISTRIBUTION of iOS apps.
Google has an EFFECTIVE monopoly on WEB searches.
So what? It’s not remotely illegal for Apple to decide how it’s own product works. The only possible point at which anti-trust law might apply to the App Store would be if Apple was at or near 100% of the smartphone market. Since it’s not even close it doesn’t matter whether iOS allows side loading because you, as the consumer, are 100% free to buy a competitors product. If you don’t like Apples approach to App Store management you can buy an Android phone, meaning it’s NOT A MONOPOLY.
No matter how many times you repeat your incorrect claim it will still be incorrect (and illogical).