Salaam. Is dawah obligatory for every Muslim?
It depends on what is meant by dawah. If what is meant is spreading brochures and pamphlets and intruding into people’s lives to talk to them about Islam (as Jehovah’s Witnesses do for Christianity), then that is not obligatory. What is obligatory is being a good example and calling those who are closest to you to be better. This shouldn’t be done in a harassing way, but as a genuine effort to make them better people and show them what is better. For more on this please see this previous answer.