"The feature is often the source of significant security issues."

(how often ? - I see ONE potential security issue there, so long since a month ?)

"Browsers currently support a ~25 year old version of XSLT"

----

As usually, the programmer basically and ignoring Users Case for his reward ($ impedance mismatch), is saying that the later is better than the former as he likes to use some JS magic (..there is nothing going on?) - because then.. he can debug it (!):

  <xsl:template name="book">
  <div class="book">
    <img class="cover" src="{cover}" alt="" />
    <div class="book-info">
      <div>..
        <span class="author"><xsl:value-of select="../name" /></span>
      </div>..
    </div>
  </div>
  </xsl:template>


  [..]
  const bookHTML = (bookEl) => html`
  <div class="book">
    <img
      class="cover"
      src="${bookEl.querySelector(':scope > cover').textContent}"
      alt=""
    />
    <div class="book-info">
      <div>..
        <span class="author">
          ${bookEl.parentNode.querySelector(':scope > name').textContent}
        </span>
      </div>..
      </div>
  </div>
  `;
  [..]