Harm Reduction Guides for Mainstream OSes?

We cannot control others. I exercise my agency and completely avoid all privacy invasive tech. I am talking about others. We do not and cannot exist in a vacuum within our highly-connected societies. Are you going to never message anyone who has an iPhone again? Never email anyone who’s gonna read that email on Windows? No. I’m asking about information on reducing harm, not your anonymous opinion about whether that’s the right approach. Your message is off topic, please leave the thread open for people who want to contribute.