My point is, if you end a practice harmful to mental health (and based on personal anecdotes from people really shocked by vestiges of it, to the point of not t

My point is, if you end a practice harmful to mental health (and based on personal anecdotes from people really shocked by vestiges of it, to the point of not taking a job, people must think it's exceptionally harmful), you'd expect mental health to improve. If mental health instead declines - sure, it could be for other reasons, and you can even try to claim it would have declined more if you didn't end the practice, but you should have pretty good evidence to back that. As such, it's a weak but non-zero piece of evidence against the practice actually being harmful for mental health.