This is new. I had written about it a while back around the irrelevance of Twitter and Apple not opening up its ecosystem. I believe this stance has changed for the EU customers:
Will Apple Allow Users to Install Third-Party App Stores, Sideload in Europe? – Bloomberg
Software engineering and services employees are engaged in a major push to open up key elements of Apple’s platforms, according to people familiar with the efforts. As part of the changes, customers could ultimately download third-party software to their iPhones and iPads without using the company’s App Store, sidestepping Apple’s restrictions and the up-to-30% commission it imposes on payments.
The moves — a reversal of long-held policies — are a response to EU laws aimed at leveling the playing field for third-party developers and improving the digital lives of consumers. For years, regulators and software makers have complained that Apple and Google, which run the two biggest mobile app stores, wield too much power as gatekeepers.
My bigger concern is Apple’s visibility into deeper consumer behaviour and financial data. Besides, they are known to “copy” popular apps and then make them redundant. I’d still regard this as a good development. I will be observing this space.