Personally, after reading up on it, I’d say like @asawyer
I see that both are valid HTML, the output is a little different though. If it breaks some of the output, a quick fix to mimic previous behavior would be:
li > p {
margin: 0;
display: inline;
}
Also, I do understand that if you’re upgrading it will be a while before you discover this new behavior. An editor makes a list and suddenly it looks different from all the other lists they made before.
We could change the defaults, but this has one very unfortunate side-effect: you’d never be able to use <p> elements in lists again (they would just be stripped). But that is valid HTML and has legitimate use cases. Using <p> inside <li> was also something you could already achieve in TinyMCE, so it would break things in different interesting ways which we’d need to find weird workarounds for 
Just for perspective, this is what two LLMs that I consulted had to say about it:
TipTap uses ProseMirror’s schema. ProseMirror intentionally encourages:
<li> <p>…</p> </li>because:
- a block-level node (like
<p>) makes editing consistent- it avoids weird cursor behaviour
- it allows adding multiple paragraphs inside one list item
- it matches the HTML spec perfectly
- TinyMCE doesn’t do this by default because it’s older and tries to emulate “Word-like” content, not necessarily semantic correctness.
So is
<p>inside<li>more correct?
Yes. It is more semantically flexible and 100% valid HTML.Plain text directly inside
<li>is also valid, but wrapping content in a<p>:
- better reflects that it’s a block of text
- allows structured content inside a list item
- aligns with modern editors
- avoids ambiguous whitespace rules
This is why modern editors (TipTap, ProseMirror, CKEditor 5) use
<p>inside<li>.