In past months Kevin has done great work to migrate several UI elements (switch, radio, checkbox) to web component.
PLEASE NOTICED that Any new patches for settings that contain those UI should use web component instead of Building Block.
Instead of using gaia-components(which comes with new UI style),
We have web component with same name (gaia-switch*, gaia-radio*, gaia-checkbox*) inside of gaia/shared/elements, ex:
They are mostly wrappers for building block style, so it has same looks and feel like current UI,
not breaking the UI consistency and with better maintainability.
There're still some switch elements need to be migrated, once the work is done we will remove all pack-[element] related css styles in settings css.