I've noted this is occurring with Twenty Twenty Three, as it does not include support for wp-block-styles re https://github.com/WordPress/gutenberg/pull/44640 — but as we're pushing for block themes to not include styles or functions, we should adapt the core/quote block to look better out of the block — both the default and "Plain" styles (although we probably didn't need to include "Plain" in core…).
It's worth nothing that the core/image block's core-provided "Rounded" style is included within the block's style.scss file — ensuring it is available, regardless if the theme includes support for theme styles.
I've noted this is occurring with Twenty Twenty Three, as it does not include support for wp-block-styles re https://github.com/WordPress/gutenberg/pull/44640 — but as we're pushing for block themes to not include styles or functions, we should adapt the core/quote block to look better out of the block — both the default and "Plain" styles (although we probably didn't need to include "Plain" in core…).
It's worth nothing that the core/image block's core-provided "Rounded" style is included within the block's style.scss file — ensuring it is available, regardless if the theme includes support for theme styles.
The quote block should probably do the same.
https://user-images.githubusercontent.com/1813435/231557562-9f54749e-ba64-45b1-b775-f178919ff0c8.mp4