The biggest issue imho is that the device is tethered by the vendor. You can't use it (practically) without being connected to Apple. This should change. I should be able to buy a product and use it with anyone's services. Otherwise, I bought a service and not a product.
You're right, and this is what the Digital Markets Act will help achieve. Though considering how tech companies behave in the face of new consumer rights (see how it took Google half a decade and multiple fines to show a GDPR compliant consent popup with a REJECT ALL button), it will be a couple more years before you can install a third-party app store on iOS or sideload an app.
