The Hebrew word hoy (woe) is used in the Old Testament to express sorrow and grief in the context of lamenting a death. “Woe” is a wailing of sadness.
But a pronouncement of woe was also used to predict impending disaster.
The Old Testament prophets often uttered the word “Woe” as a part of their prophecy against a nation. It was designed to shake people up, to make changes.
It’s worth noting that Jesus expressed sadness over the end of those who follow their own ways. That’s why he warns us about the impending disaster if we continue down that path.