Social skills, as the name implies, are meant to be trained, maintained, and expanded over a lifetime so don’t discount yourself because you feel like you’re too old or have tried and failed for too long. Have you considered seeking behavioral therapy? Perhaps you’re not picking up on the myriad non-verbal social cues that could help you better inform your conversations. Behavioral therapy can help identify where you’re lacking and give you the opportunity to practice skills and receive feedback from a professional.

I sincerely wish you the best of luck.

You don’t need to give explicit details of your coworkers’ lives, but from your writing it really seemed to me that you were more interested in mechanically optimizing conversation. This isn’t necessarily a bad perspective, but people already do that organically by understanding each other more and learning their history. The route of good conversation follows logically from there through empathy.

You’re descriptions kind of make your coworkers like NPCs. If you want to have better conversations you should probably get to know them better as people. That can allow you to understand the why of their particulars and eventually guide your conversations more organically.