In ArcView 3 (AV 3) users often created multiple layouts and disconnected the live link to each one. The AV 3 help text below briefly explains what we could do in the program.
Add a view
To create a map for output containing geographic data you must first add a view to your layout. When you add the view you can choose to make it live linked. This causes any changes in the view to be reflected in the layout. If you decide not to live link your view, it will not change in the layout even if you make changes to the view.
Layouts were not especially powerful in AV 3, but users could create multiple static objects and print them as displayed.
In ArcGIS Pro, multiple layouts are available for within a single Pro project and multiple layouts are associated with a specific Pro map within the Project. In each layout, the user specifies the extent, layers displayed, cartographic elements, and more. In each individual Pro layout, the user now refines/updates the associated map, before printing or exporting the layout. If the map is modified later, the layout changes, too.
It would be very helpful to lock individual layouts to preserve user settings and parameters, without modifying the underlying map.
I strongly recommend that this feature should be submitted as a near term enhancement. I, and others, once used this AV 3 feature often.