It's not because you can still install apps outside the Play Store. The EU commission buys these "safety" arguments (also worked for Apple, they don't care that you still can't install IPAs) and the DMA is made for businesses, not for end-users. I once wrote them about the Chrome Web Store monopoly but they insist that everything is fine because businesses aren't impacted. They are of course also interested in centralized censorship because they can order Google to block apps they don't like.