If you succeed at changing your habit, it works.

However, all the evidence is that the vast majority of people fail at changing their habits in ways that produce lasting weight loss, so it does not generally work as advice for reducing your weight.

So you're technically right, but it is irrelevant, because we don't know how to actually get people to change habits with any meaningful rate of success.

At this point it is downright harmful and wildly unethical to recommend it when we now have a far more successful option.

You didn't say "trying to change your habits" don't work. You said changing habits don't work. This is false, harmful and wildly unethical.