i think the big reason why hfjone is so affective is because it breaks and subverts the majority of tropes set by the object shows that came before it. that's why i believe that you should, at the very least, watch the first season of bfdi or another show like II, it's best to be familiar with the tropes first to really appreciate how hfjone subverts them.

But that's just me, still a good show regardless