Maybe you’re right in this case, but I find it impossible to believe that apple would allow third party apps ever, if not for regulatory intervention. Given that the existence of Android has not caused that to happen naturally yet, there’s basically no other chance that any other market player would be able to reasonably upset that. Same with google search, Bing and Baidu have a laughably small market share in search, despite both being multibillion dollar companies behind them. And forget small players like DDG or Pinephone, they don’t even register on the charts.
So yeah, market regulation is necessary here, I’d rather roll back useless regulation later than continue with the status quo.