Why does a higher market share in the US have any significance in this discussion? According to [1] the US only accounts for about 10% of the global smartphone market. As an Australian, I couldn't care less about their US market share.
And even if we go by 45%, that's still not close to a monopoly. You're not by any means forced to publish apps on their app store.
And even if we go by 45%, that's still not close to a monopoly. You're not by any means forced to publish apps on their app store.
[1] https://www.countriestoday.com/smartphone-users-by-country/