Ignoring the art and fashion behind much of it, much of the style comes from the industrial revolution era. And that’s not entirely a bad thing.

Before plastic, there was copper and brass. Easy to work, inexpensive and fairly durable.

And the how practical was what i was thinking of.
The clothing styles have changed, but we’re still wearing wool, cotton duck (carharts), denim and so on.

Granted the top hats and bowlers may be bit silly, but not that long ago a man or woman wasn’t fully dressed without a hat. Look around today, at all the ball caps, while not “proper” they do continue the tradition.

How much from those years survives and still functions? That kerosene stove still runs while that microwave from 1990….
How many preppers are going old school? Old knives and axes, old tools? Because they last and work better. My wife just got a new set of pans, her last was around 20 years old and were no longer non-stick. Whereas my 100+ year old cast iron pots are still the same.

These steampunks may not know it, but by adopting all this, perhaps they are setting themselves up for success, however accidentally.