I have one module called Test_A. We can override any layout of Module-theme in Test_A by giving the same name.
Ex. Module-theme/view/frontend/layouts/frontname_controller_action.xml
can be override by creating file
Test_A/view/frontend/layouts/frontname_controller_action.xml.
But how can we override Module-theme/view/frontend/layouts/default.xml in My Module.
Why we have to create custom theme for it?
We can't modify any module's default.xml layout?
default.xml
from theme into your custom module ?default_head_blocks.xml
as Magento recommend :app/code/Vendor/Modulename/view/frontend/layout/default_head_blocks.xml