The words 'downfall' and 'kebinasaan' look related at first, but to me they live in different semantic neighborhoods.
'Downfall' usually points to a decline or fall — often of a person, reputation, regime, or institution. It implies loss of status, power, or position: think 'the downfall of the emperor' or 'the scandal led to his downfall.' It's dramatic, but it doesn't always mean physical destruction. In Indonesian you'd often render that as 'kejatuhan', 'keruntuhan', or 'kehancuran' depending on nuance. 'Kebinasaan', by contrast, feels terminal and absolute; it carries the sense of annihilation, extinction, or utter
ruin — more like being wiped out than merely losing a throne.
So when I read historical or literary texts I translate with care: a fallen dictator might suffer a 'kejatuhan' or 'kehilangan kekuasaan', while a devastated species or a city turned to dust leans toward 'kebinasaan'. The tone matters too — 'kebinasaan' is heavier, often moral or apocalyptic, and not the casual counterpart of 'downfall' in everyday speech. Personally, I like spotting which shade the author intends because it changes the whole emotional frame.