It should be easy to configure, but I don't think that behavior should be the default since it's less general and only works when you press Return from certain types of blocks.
Shift + Return also isn't available on mobile. And it's annoying having a hidden key combo just to get behavior you want. I seem to regularly battle with Reddit's rich editor that does this.
All to save me from having to press Return twice.
Though I can appreciate the niceness of how clean it is to always keep the user inside a <p style="margin-bottom: 2em"> while making them opt (with Shift + Return) into a <br>, I'd yield to UX over cleanliness when it comes to something as finicky as rich text editors.
Plain text return = new line.
Rich text return = new paragraph (shift + return = new line if you want).
This was a big problem for me with earlier versions, unsure how customizable this behaviour is now.
I do appreciate that I probably care too much about this, but I found TipTap worked well.