In the Agent AI Era, How Often Will We Need to Use "Apps"?

Back in the early days of personal computing, applications were loaded onto individual PCs. In the following client-server era, the apps were mostly loaded on local servers and accessed by individual PC clients. 

In the cloud computing era, apps reside on remote servers. In the agent AI era, functions might be invoked directly from AI apps, without the need for discrete applications. 

We are starting to see glimmers already.