This doesn't have anything to do with privacy.
The DMA mandates that Apple allows for competition, which (if you believe in capitalism) is good for the market overall. It's essential to stop big tech from abusing their market dominance. However Apple would prefer to not allow competition for their digital products on any of their hardware.
Siri AI has the capability to read your screen and access a lot of personal stuff. I don't blame Apple for not wanting to open this up to allow any model to access it. It seems Apple proposed a number of solutions which were denied.
While I can appreciate the reason for the DMA, people don't have to buy Apple devices, they can buy any type of phone they want and just use the ecosystems provided by these phones.
We already have choice - people can buy many different types of phones. Nothing about this is about choice or the free market. They want special treatment.
Apple is free to do what they want. The EU can go and try and build their own iPhone (good luck with that).
But that does have to do with privacy.
Apple wants to implement features that access data locally. It doesn’t want to allow competition for offering those features, but if it did, competitors may use that access to local data to exfiltrate.
So it is about both competition and, as a result of creating competition, privacy.