You can use any smartwatch or earbuds with Android, there aren't private Google-only APIs for those things.
Apple also has a big enough marketshare to matter to the DMA.
Apple also has a big enough marketshare to matter to the DMA.
You are comparing Apple's primary product/service against a throwaway part of Google's. Google has walled gardens around its primary business too. But they are so deeply ingrained into our world that nobody questions it, because there's also no viable competitors.
Criticism of Google is fair, but it has nothing to do with excusing Apple here.
Maybe the EU can ask Google to open Chromecast up so Apple can integrate it into iOS. Then you can use it from any app without needing special integrations.