Should fieldsets be nested for yes/no questions?

Forms with yes/no questions that reveal new questions depending what you select... Is it "most correct" and most useful for those who are dependent on accessibility to have the new questions pop up after the fieldset surrounding the yes/no question, or inside the fieldset?

Example, with pseudo-html:

<fieldset>
  <legend>Do you like food?</legend>
  <label><input type="radio" name="like_food" value="yes"> Yes</label>
  <label><input type="radio" name="like_food" value="no"> No</label>

  <when like_food = yes>
    <fieldset>
      <legend>Do you have a favorite food?</legend>
      <label><input type="radio" name="have_favorite" value="yes"> Yes</label>
      <label><input type="radio" name="have_favorite" value="no"> No</label>

      <when have_favorite = yes>
        <label>What's your favorite food?</label>
        <input type="text" name="favorite_food">
      </when>
    </fieldset>
  </when>
</fieldset>

vs

<fieldset>
  <legend>Do you like food?</legend>
  <label><input type="radio" name="like_food" value="yes"> Yes</label>
  <label><input type="radio" name="like_food" value="no"> No</label>
</fieldset>

<when like_food = yes>
  <fieldset>
    <legend>Do you have a favorite food?</legend>
    <label><input type="radio" name="have_favorite" value="yes"> Yes</label>
    <label><input type="radio" name="have_favorite" value="no"> No</label>
  </fieldset>
</when>

<when have_favorite = yes>
  <label>What's your favorite food?</label>
  <input type="text" name="favorite_food">
</when>

The first one, means "Do you like food?" will contain more than just the radio-buttons to answer that question, but it also means it's possible to "drill down" into that "group of related questions", which I've found to be helpful when testing with e.g. findByRole('group', ...). But I don't know if it would be equally helpful for people using assistive technologies, or if it would actually make it more confusing.

With the second option, it's not possible to "drill down" into the groups, but each fieldset with a question in the legend only has the radio-buttons to ask that particular question.

Any advice? What is "most correct" and best ux here?

Added: Screenshot of such a question on a (norwegian) website. The first question is a yes/no question. The second question only appears if the user selects "yes" to the first one. Since the fieldset doesn't have any frame or padding, it looks the same whether the second fieldset is inside or after the first one.