As a Solution Architect, you need to know what Power Apps type is best suited for the customers' requirements.
There are three types of Power Apps applications:
Model-driven - responsive Dataverse data-driven applications. This type is more data administration with a back-office and process focus.
Canvas - flexible phone or tablet applications that can use multiple data sources. The canvas app is focused on the end-user and helps to execute a particular task.
Portal - external websites for interaction with Dataverse data. It has the end-user focus.
Your architectural solution should not be monolithic. But it should not contain a lot of small apps either. You need to find the best composition for your solution between three main Power Apps types, Dynamics 365 functionality, components, and other AppStore apps.
Reference:
https://docs.microsoft.com/en-us/learn/modules/power-apps-architecture/3-composition
https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/add-reporting-to-app
https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/embedded-canvas-app- add-classic-designer