they were never equipped to fight or put a stop to fighting. they are just observers equipped only to defend themselves if they are personally attacked.

what is their purpose now? well I suppose now they are helping make isn'trael even more of a pariah by not moving on their illegitimate orders and being used as human shields. But them continuing to observe is also good, the IOF wants them gone or dead for the same reason they kill journalists. They don't want third parties reporting their war crimes.