I worked this out in 2008. Nothing is ever going to be good enough because the actual problem is they can't change sex and deep down they know it.
So the response is of slow anger to punish the world around them for this. Whatever you do it will never be enough because you can't change reality and you can't change how they feel about themselves. All this proving that transwomen are better at being women than women is exactly that - punching down and punishing others for what they know and see in the mirror. It doesn't matter how nice you are, how kind you are, how accommodating you are - you can't change what they see staring back through the mirror at themselves.
I do think it's effectively a form of self harm. Showing allyship is enabling and supporting self harm.
If you love someone and want to help them you don't achieve this by supporting the self harm. And it's like addiction in many ways - until they are ready to acknowledge that there's a problem and they can't change sex and look for support in other ways you can't actually help anyway. Those who affirm just feed the addiction.
But like all addictions, even your most supportive friends and family have a breaking point and eventually if the demands continue they do say 'enough' because they realise they can't actually help and what they've been doing ultimately contributes to the problem.
This is why trans parents who have been enablers will always be the last ones standing too. Because they have to admit they were the dealers who got their kids hooked on the lie before they were old enough to understand. Transition at age 3 is like giving you kid class As age three. Which they will never admit precisely because it means an admission of negligent or abusive behaviour.
This is difficult and controversial to say. I'm yet to see anyone who ultimately doesn't fit this pattern though. I think you notice it more the closer you are to the epicenter you are. It's why you get people who have trans friends saying how lovely they are and knowing elements of the self loathing but not understanding the lashing out part well. JKR is the lightning rod for the lashing out though which we can all easily see.
It's a fascinating psychological social experiment playing out in real time. I just wish it wasn't actually real though.
You have to know the difference between dreams that might come true and fantasies that can never ever come true.
There is no magic bullet anymore than there is for stopping gamblers with a problem with win euphoria or drug abusers who just want to shut out the pain. Or anorexics desperate to control their lives. Unless you deal with the underlying stuff that drives it all, no you will never be happy. And actually this isn't my problem to fix because the only person who can ultimately make yourself happy is yourself. Happiness can not ultimately rely on others. It has to come from within.