The Republic becomes the Empire. The Empire does not become the New Republic, it becomes the First Order.
Honestly we’re not given a precise answer to this. In the outer rim territories, looks like that’s it. But I’m not sure that’s the same situation in the inner Core systems.
The Rebels form the New Republic, and later the Resistance.
The fact that the Resistance is sort of a fringe, unoficial faction of the Republic might help explain the use of guerrilla garments. But in VIII, after the escalation of the conflict and an open attack on the republic, I don’t think they could still keep showing the good guys as a poor band of outcasts. They are in control of the wealthiest systems of the galaxy
It would be very strange if these teams swapped uniforms, so to speak.
Yes, both ways would make sense in the end. I’m secretly hoping for both teams having different versions of stormtrooper armor. But probably we just won’t be getting that.
The First Order’s stuff is new and spiffy because so are they. That doesn’t make them in charge, and they’re not. The Resistance is scrappy because they aren’t in charge either, they’re a separate group created by members of the New Republic. As to whether or not they should have armor is a legitimate question but in my mind it would make no sense whatsoever for them to look like stormtroopers.
The thing with the First Order having top tech and being all shiny and new might not be just a design flaw, but rather expose some of the weaknesses of the movie’s plot. At least with what we have been told so far.
If their take was, as Abrams said, to think of the FO as a what-if scenario with the nazis hiding in Argentina, I think they just didn’t make enough research about what happened down here.
I can take that admirers of the old Empire would still honor its aesthetics. I can even take that a splitting appendice of the oficial government would look and feel poor funded. I can a galaxy-wide regime having enough resources to build a superweapon the size of a moon. But it is far more difficult to accept a band of outcasts being able to fund the transformation of an entire planet into a sun-sucking superweapon the upsaid regime couldn’t even afford.
Let’s see what approach they take with Episode Eight, where the New Republic is to be a warring faction. In the meanwhile, I think that clearly these design choices weren’t made under an in-universe logic, but rather with an outsider perspective. Bad guys don’t show their faces and hide beneath masks while the freedom fighters are humans you can get invested with.
The first gesture of the defecting soldier is precisely to take off his helmet.