They somehow separate out certain apps, like Safari (on occasion), the iWork suite, and the Pro apps, but I have no idea why they insist on coupling apps like Photos and Music to OS updates.
In Sonoma or Sequoia they started bundling all Safari updates with macOS, but right now Safari 26 appeared as a separate update in Sonoma/Sequoia—-and it will likely stay that way.
Each thing separately can be explained, but when put together it’s somewhat messy..