Should "Enter" create a large or small line spacing on text editors?

On some popular rich text editors like CKEditor, the default behaviour for pressing "Enter" is to create a new paragraph (a <p> tag), while on the others, like the textarea here on Stackexchange, pressing "enter" would mean a line break <br>.

Things get complicated when users are copying from one editor to another editor. For example, if a user write his/her work on Microsoft Word, where the user need to press "enter" several times to create enough space for a paragraph, copy and pasting it to CKEditor would create unintentionally and ugly large gaps between paragraphs. It seems that I can configure CKEditor to make it Enter as <br>, instead of Enter as <p>, but is it really better if the editor on my site is intended for writing long passages with multiple paragraphs?