Drupal core's admin theme Claro styles field-item to have margin-block: var(--space-l); which is very important for the spacing of forms.
In general i think form-item is expected on items in a form for consistent styling.
Adding the class with a template override is not convenient because it is on the suggestion-less container template (although it is possible
Twig Template Suggester →
could help with that).
Add this class, possibly with an option to add it or not.
Active
2.1
Code
Seems the best solution, despite adding one more nested div, is to add the form-element template as a wrapper, which should let all themes treat form items as they thing they should be treated.
Happy to add a configuration option for this, disabled by default, if at most we want an optional change that does not impact existing sites at all.