Public domain data: Publishing details that were already legally accessible in public records or voluntarily posted on public social media profiles. Lack of specific statute: Many jurisdictions do not have a dedicated criminal charge explicitly named "doxxing," meaning prosecutors must rely on general laws covering mischief, harassment, or uttering threats. Dude posted the picture himself. I did not need his consent to save it.
I don't even remember where I originally posted that image. It may have been a DM or a temporary upload rather than something I left publicly accessible. So you're treating “you posted it yourself” as though you've established that it was permanently public, when you haven't. And even if it was publicly posted, publicly accessible does not mean public domain.
More importantly, this is exactly why I have reason to keep further personal information away from you. You retained an old image I don't even remember publicly leaving up, have repeatedly brought it up for years, use it as an ad hominem, and now insist that I have no right to object because I supposedly “posted it.” Your response to my concern is itself evidence that I have a rational reason to be cautious about what information I give you.