I must be a weirdo.... I just wear lots of wool, and a thin windproof/rainproof jacket with armpit zips. I get sweaty but I stay warm (as long as I'm moving)
The modern materials can be effective while being very light weight and take up little space. But I think these are much more niche concerns than most people like to acknowledge.
I think the real reason the modern materials are more popular than wool+ is that they are more profitable when marketed, and hence are heavily marketed.
But generally speaking I do think we're going a bit crazy with the exotic materials in travel/active gear. It's probably just not necessary for a lot of people's use cases.
It is a bit on the heavy side, though. Not really good for sports/cycling/etc, I wouldn't imagine. Also gets a bit ratty/threadbare wherever it gets repeatedly creased and un-creased.
But it really does work, and is long-lasting. I had previously been buying a new raincoat every few years due to some tiny crack in the waterproof layer that can't be easily fixed.
There's probably no perfect solution here but this definitely isn't a direct replacement, though sure it's practical for a lot of applications.
Here in Denmark, "Fjällräven" is a household name to the point that it can be used to refer to their small backpack model.
Perhaps soy wax could be used for this...
At least if we use beeswax we can approach it sustainably, filling the world with microplastics doesn't seem like a sustainable thing to be doing.
You get the warmth from something else underneath use the very thin Shakedry shell to keep the rain and wind out. Except that with a breathable fabric you won't get (as) sweaty[1].
If you pair it with arm and leg warmers you can cover a really big temperature range, like you might encounter on a multi-day cycling tour without taking up much space or weight.
Despite the marketing you can still get a bit sweaty with Shakedry if it's hot weather.
Not everyone has the option of “just don’t stop moving”.