Look at the images, 'Apps' mentioned multiple times. 'Apps' is where the new UI wants to take users, it didn't exist until recently. 'Space apps' has been buried. Not all apps have yet added a global page (this is new) which what is required for an app to show under 'Apps'.
I'm a content person, I was a journalist in another life. Now I'm on the other side building Confluence cloud apps. While I think Atlassian has finally cleaned up the Confluence UI, it is so much better, they created confusion in the short term and have legacy issue mean it's like 80% create and 20% confusing (while Notion is less powerful but less confusing).
Technical people talk up features and tend to avoid the 'tree falling in a forest' problem of confusing UI or too much bloody work to bother.