Feelings are real. But they are not facts. Poverty of aspiration is a real feeling. But material poverty is a fact. And gender identity is a real feeling. But biological sex is a fact. Those who have sold the pass on the first point cannot hold the line on the second. Or vice versa.
To insist on biological sex is to ensure that Mark who was once Marcia is still called for a cervical smear test, and that Simone who was once Simon is still called for a prostate examination. It is precisely to treat transgender people with equality. There is no equality without economic equality. And that was where we came in.