WordPress 6.9 introduces two new elements to theme.json: textInput (for both inputs and textareas) and select:

• Global styles: add element support for text related inputs gutenberg#70378
• Global styles: add support for select or dropdown elements gutenberg#70379

We should have a tutorial that walks theme authors through using these, which Core blocks they affect, and encourage testing with third-party plugins that contain forms.

Note: there's still one big limitation with this feature: no state styling. For example, these do not support things like :focus, so custom CSS may still be required. There is a PR to address that, however:

• WIP: Add pseudo elements support for textinput elements gutenberg#71634