... is an oxymoron.
It is plenty obvious from a quick scan of https://reddit.com/r/minimalism where they struggle with reconciling all different interpretations of minimalism on daily basis. For some it's asceticism, for others it's having just one Rolex instead of 10 Seikos. There's also a separate circus from the "Help, my SO wants to buy a 2nd fork!" variety.
There's no single prominent movement, it's very much all over the place and to each his own.
It's one and the same really. Once you have a bit more money the pragmatic live-in-a-shoebox minimalism tends to transform into the "aesthetic" variety - you still own a bare minimum that makes you happy, but you can now afford a better quality of the same. Be it a larger place or a more expensive pair of jeans.
"Need" is subjective and the rest follows from there.
>Minimalism is a lifestyle that helps people question what things add value to their lives.
The movement involves reflecting on your personal values, so of course it's going to have almost as many expressions as there are people doing it.
While it can be taken to the extreme, the underlying premise is true. Buy a new car and you're going to be worried about taking care of it. Buy a used car and you're a bit less worried b/c it already has some scratches. Don't buy a car at all, and you're never worried about the car (maybe how to get places if you don't live in a city...)
The goal should be to only add things to your life where the value is more than the costs. One situation where people have huge differing opinions is kids. Kids probably cost more than anything else someone can obtain in life. They are expensive money wise, time wise, and emotionally, but for some the value is huge, and others not so much.