Conspiracy theory:
There is no parent CSS selector because Google effectively controls web standards, and if that existed then it would be extremely easy to hide ads, ruining their business model. Do you a-- help help they've got me hehgxh dry jvcgk cc d

*shaky voice* I would like to apologise for my... *Whisper: what was I supposed to say again?* outburst of crazy conspiracy theories. I need hel- *gun click* *clears throat* The above rant is totally fictional and was not meant to be taken seriously. Once again I am sorry for using my free spee- *muffled voice: I'm warning you*... for my serious lapse in judgement. *whisper: is that ok?*
*gunshot*
*scream abruptly cut off*
*pause*
*incoherent gagged mumbling*

Well IDK about google, but there's also no "previous sibling" selected while the "next sibling" exists, so... guess most people just don't need the parent selector (?)

*KNOCK KNOCK KNOCK*
FBI! OPEN UP!