I would think most peoples ideal is to live in healthy natural commmunities with a diverse age range to get wisdom and tradition from the old and energy and new ideas from the young.
Though things that are harmful without benefit tend to die out over time.
So while tradition doesn't make something magically useful, many traditional things are useful, often in unobvious ways. Of course, many do not...
The hard part is to recognize if the reasons for the previous success still apply in the modern world. See "Chesterton's Fence".
Not at all. Traditions become traditions over long periods of time. Thus, they tend to be collections of things that haven't caused a societal failure in the last several hundred years, which is a much better record than not causing immediate failure.
(Yes, this is absurd. Yes, I've told him this is clearly a bad idea. Yes, it's actually true.)
Which is to say one should be cautious of survivorship biases and the role of context. Judging traditions as successful based on a limited context where they haven't obviously failed both ignores the situation upon which they may depend and other scenarios where precisely those might have failed. Like the other people who have tried what my friend has and been rendered into chunky salsa for it.
So yes, traditions are typically worthwhile, just not necessarily for their apparent or stated purposes.
... Jews have close to five hundred different dietary interdicts. They may seem irrational
to an observer who sees purpose in things and defines rationality in terms of what he can
explain. ...
But it remains that whatever the purpose, the Kashrut survived approximately three millennia not
because of its “rationality” but because the populations that followed it survived. It
most certainly brought cohesion: people who eat together hang together. Simply it aided
those that survived because it is a convex heuristic. Such group cohesion might be also
responsible for trust in commercial transactions with remote members of the community.