It's true that not all signaling and status posturing is bad. What happens is that we recognize how destructive so many of our signaling and social status tendencies are, but then apply an overly general heuristic of, "Avoid doing anything we could refer to as status posturing or signaling."

It's certainly the case that a lot of the status behaviors are dangerously mal-adapted for our current environment (especially when it comes to our epistemic rationality), but not all of them are, or rather most of them probably aren't--it's just that the destructive ones are most visible.

This also happens with food. People notice that the output from our taste buds is alarmingly mal-adapted to our present food selection, and that (at least for most people's utility functions) just because something tastes good doesn't mean you should eat it, but then they overly generalize and end up with a heuristic that completely dismisses taste as a useful indicator. It's not that you should never listen to your taste buds; it's just that you need to know when to do so.

Just as removing the junk from your food selection and replacing it with a wide variety of traditional food helps re-align the indicators and allow your taste buds to become trustworthy again, putting yourself in a better social situation will lead to something similar. I certainly trust my status posturing tendencies more when I'm on this website than when I'm hanging around with a bunch of comparatively irrational, incompetent people.

If you want to know whether a signaling or status behavior is rational or good, just ask yourself whether getting social props in the situation at hand is well-aligned with being successful in the other ways you care about (just like considering whether some food tasting good is well-aligned with it being healthy and providing the right nutrients). If the answer is no, then ask yourself how you can re-align them, or else avoid the situation--unless of course the social props at stake are what's most important to you.

Not all signaling and status behaviors are bad, just as you don't need to stick to just bland, uninteresting food to lead a healthy lifestyle.