Why do enlightened beings want to save sentient beings? Does everyone want to be saved?

Does enlightenment always comes with compassion so that all enlightened beings aspire to save sentient beings from sufferings? Or is the question 'why' only showing that I am using my discriminating mind to try to understand things? Another part of my question is that I think most of the people on this earth would not say they are 'suffering', there might be obstacles and negative feelings from time to time, but most people enjoy getting attached to the experience of pleasure, longing, love, etc. Most of them enjoy this worldly life so much that they wouldn't even thinking of standing back out and look at this kind of life that everyone is living from an 'outside' perspective. So my question is that why would all these sentient beings forgo this mostly pleasurable life (with net happiness larger than unhappiness, and all sorts of biological/neurological signals from their bodies guiding and incentivizing them to continue living and reproducing for the continuity and advancement of the species) to practice Buddhist teachings, to let go of things and pursue the state of nothingness? For most of them, it would be giving up net positive happiness to attain a state of nothingness and tranquility. Is that what everyone wants and needs? How do you convince them to do this? How do we save ALL sentient beings? Should we do this? Why do enlightened beings do this? These questions have been tormenting me for some time. Would be great help if someone can help me understand them. Thank you!