It's not, FlexDiv is just another name for Stack, they are describing the same aspect. Eg. you can imagine one CSS library using Flex, one Group and the third one Stack for the same concept, eg. some other UI frameworks use VBox and HBox. But it is still different from TopSectionHeader, SectionHeaderInner, SectionBodyWrapper, or whatever other names you have to come up with to give your component "semantic" meaning according to their content.
> to give your component "semantic" meaning according to their content.
This is one of the biggest pros for Tailwind, is that it leads people away from this misbegotten mindset. The scare quotes around "semantic" are right. It's amazing how many of the same people stress separation of concerns to separate content from presentation, then turn around and name the presentation after the content.
