I believe that to do what you need:
From UI Builder, go to the Service Operations Workspace experience.
Duplicate the one you want to modify: "Record (SRP)" (assign it a lower order so it appears instead of the default).
Select the "Overview" tab and click "Edit Content".
Create a variant of "Incident Overview" (with a lower order), edit it, and there you can remove the Cause section (or anything else you need).
Pending doubt:
The fields in the Overview "Summary" component are displayed using the default view "SOW-Incident-Overview" (by modifying its "related list" Summary). I haven’t been able to modify the component to use a custom view I create instead of the default one 😞
