What do you think of the need for food to be traditional ?

tradition is peer pressure from dead people

There's a place for both. I'm French and I don't like it when you take traditional dishes or items, butcher them and still call them the original name. However it's totally fine if you want to update the recipe, make it a fusion with something else, or whatever else you fancy, but just give it a different/updated name.

It depends on the context.
If I'm celebrating a holiday or cultural event, it is good to skew closer to tradition as the food is part of the tradition.
Outside of that, tradition was just optimizing to the cooking techniques of the time. I like Adam Ragusea's analysis when discussing spaghetti and meatballs. The context of the recipe 60 years ago was that it was a high scale recipe for a large extended family, a context they doesn't fit most uses today.
- Not to mention that spaghetti and meatballs itself is a fusion dish invented in America; it's not traditional Italian cuisine.

Food needs to be traditional as much as it needs to be modern.
It's great we are still pushing culinary boundaries, but sometimes you just need a comfort food.
Traditional dishes remind us of where we've come from, either literally reminding us of our homeland if we've moved, or reminding us of our ancestors, or figuratively by making us think of our childhoods or of grandma's famous holiday sides.
It's the reason we eat green beans casserole on Thanksgiving, but never any other day of the year, or why we still crave a PBJ or Hot Pocket.

Silly. If it's tasty it's tasty

Eat what you enjoy eating.
Ferinstance, I add green onions, thai green chiles and lemon juice to my pesto. It's greener and zingier and steers away from that fusty-old-deli direction that it can otherwise go in. It's not even remotely trying to be authtentic or traditional, but it sure is tasty.

Most places I've been, people want to eat their usual food they've eaten for generations.
None of my business to tell em they're wrong.

It is extremely harmful per se. Tradition is not an ethical or healthy reason to eat something. However, there is a strong correlation between certain traditional diets and human health. But not because they are traditional and that should not be used to justify or promote their practice. Such arguments are also used to rationalize absolutely needless cruelty, violence, and atrocity that even harms the practitioner.
- Tradition is not an ethical or healthy reason to eat something.
  Given that novelty is a predictor of inflammation, I would say tradition is a healthy reason and thereby an ethical reason to eat something.

Who has this need?

Traditional is fine when its a good tradition.
Now to preface this I am very white, but my whole life Ive heard from people that "My great grandmother brought this recipe over with her on the boat" and I have to bite my tongue not to say "Yeah but could she cook?" In a rural town of 50 families there has to be one woman who is the worst cook in town and theres a non zero chance it was her.
I am absolutely the best cook in my extended family on both sides because I read, research, watch, practice technique and experiment.

I mean, if I'm experiencing a culture for the first time, I'd like the food to be as authentic as possible.

No. The best meals are a fusion of eastern and western cultures.
Is a Bunnings snag traditional or is it a knockoff of a hotdog?

What's traditional? Like some decades or 100 years ago? Or before the Spanish brought the potato to Europe? Or paleolithic diet? I don't quite get what "traditional" means in the context of something always changing and evolving like food. And plants like potatos, tomatos, paprika, coffee, ... and spices spreading over the world. And a constant flux of change and everything being connected and incluencing each other for centuries or thousands of years already.
Or does traditional mean not as much additives, sugar and convenience food? Because I think we can answer that by looking at the statistics. People need less sugar and more fibers for example than we currently consume (on average).
- Or before the Spanish brought the potato to Europe?
  Prior to the Columbian exchange, the Old World had never seen the tomato, the potato, corn, or chocolate, to name a few notables. The New World had never seen rice, wheat, beef, pork, or chicken.
  It was a very different world for both from a culinary standpoint, that's for sure.
  
  I suppose where I live they mostly ate food made from grain. Like bread or barley gritz or other tasteless stuff. And then some available vegetables, berries, some animal produce, probably not a cow unless they were rich, more like eggs and occasionally a chicken.
  I think the Roman empire also spread quite some culture and food across Europe. But I can't imagine living before the Columbian exchange. That brought us most stuff we eat as if today. Yeah and colonialism in general, that made some goods available for people in Europe.