It's because interacting with the app felt like interacting with a page in a word processor. e.g. in Microsoft Word, if you select Heading Style, type heading

It's because interacting with the app felt like interacting with a page in a word processor. e.g. in Microsoft Word, if you select Heading Style, type heading text and then hit enter, the cursor is moved to a new paragraph (with the style automatically changed to body text or similar). LibreOffice Writer does the same.