More than a decade ago the EU forced manufacturers of mobile phones to commit to one standard for power plugs. Everybody used micro USB except Apple.
Microsoft had to pay a huge fine because the didn't let the user choose which browser they wanted to use and simply brought the Internet Explorer as the default with every Windows. Apple still doesn't even allow users to install alternative browsers. Yes, from the outside it looks like you can install a Firefox, but inside it is still a Safari for which Apple denies building critical APIs like e.g. the Push API [1] (which is available for all major browsers except Safari and the use cases go far beyond push notifications, like chat apps and background synchronization of data).
The App Store is yet another example. Many other platform providers allow you to install additional Software through other means than the default source (Android, Windows, Linux, etc.). I am glad a major player like Epic takes the issue head-on and hope, that in the end the eco-system will benefit as a whole.