The goal from the EU was clearly to make iOS have an android level of openness, and it seems to have failed at that and apple has made the experience altogether worse in retaliation.
For the record - I’d love to have side loading on my phone. I’d love to be able to load IntelliJ on an iPad, but it is not the place of a government to regulate how a company is able to use their own platform that they developed with their own money and tools. It is not a monopoly, android exists so there is still user choice. Are we going to start worrying about the inability to download doom to your Samsung fridge because it doesn’t offer user choice?
I’d argue that this isn’t a good example of an effective anti monopoly regulation, it’s a good example of how government regulation tends to just result in things being worse and more complex as everyone enters a race to sidestep.