For years, this has been one of the main complaints against iOS: how it's a walled garden that doesn't quite give many third-party apps the same amount of privilege as many Apple-made apps get, and this changes with iOS 14.
While this opens way to many third-party apps, it really is a huge opportunity for main rival Google: you can now have Chrome be the default browser and Gmail be your default email client on an iPhone.
At the same time, this is not quite fully opening the ecosystem: you will still NOT be able to set different default apps for Camera, Maps and Music. So, sorry, you still can't have Spotify replace the Apple Music application and Google Maps for your mapping services. Maybe next year. If it happens, we'd bet it would be in the small print of another slide.
In case you missed it, iOS 14 now also supports widgets and has an app drawer, and we're not even kidding. You can learn all about the new iOS 14 features here. And if you are wondering when the iOS 14 release is happening and what iPhones will get the new version, we have also got you covered here.