Is it Islamically permissible to continue working at a usurious bank while attempting to highlight the downsides of usurious loans and recommend Islamic alternatives, or must one leave, especially given the availability of another job with a better salary?

A Muslim is not permitted to work in usurious banks, because all those who work in them are collaborators in usury, whether directly or indirectly, and assisting in usury is forbidden. The Prophet, peace and blessings be upon him, cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses, and said: "They are all equal." This includes the prohibition of assisting in falsehood.