The Layout Builder module has been expanded to alter the site builder experience when managing the display of fields.
Similar to the Layout Builder UI for managing customized layouts for individual content items, when the layout builder module is enabled, the same functionality is now used to manage the default display of fields for any view mode.
On the "Manage Display" page the former table of fields is replaced by a link to manage the layout:

Clicking "Manage layout" will bring you to a sample representation of your display:

The existing fields can be edited using the off-canvas dialog:

If the layout for a specific content item is customized, it can now be reverted to use the defaults:

Please note, there are many known UI improvements to be made, follow along here.
| Attachment | Size |
|---|---|
| New "Manage display" | 30.91 KB |
| New "Manage layout" | 171.54 KB |
| Configuring a field block | 45.18 KB |
| Layout Builder UI revert button | 109.02 KB |