Debian does include &#x2F;opt and friends, as required by FHS:
<a href="https:&#x2F;&#x2F;sources.debian.net&#x2F;src&#x2F;base-files&#x2F;9.6&#x2F;debian&#x2F;postinst.in&#x2F;#L63" rel="nofollow">https:&#x2F;&#x2F;sources.debian.net&#x2F;src&#x2F;base-files&#x2F;9.6&#x2F;debian&#x2F;postins...</a>