It seems to me all debate misses the point. There is a large portion of the population who refuse to believe trans people exist (who refuse to believe a lot of science exists, from climate change to evolution). Trans people simply are, and a measurable 0.5% of any given population. We get distracted by hypothetical "moral" arguments (changing rooms) that are virtually irrelevent. Just as in evolution and climate change, the solution is to let the truth speak for itself, to shrug off debate, to not engage. It takes time, but we'll get there. Acceptance is the last stage of grief, the death of a worldview. There's no point in engaging with those stuck in denial and anger. It's not productive.