No. It is important to remember that all materials have different properties and impacts, and that none is perfect. Vegetal materials (like cotton, jute, hemp…) are neither better than animal materials (like wool, leather, silk…) nor better than synthetic materials (like polyester, nylon, viscose…).
Here are a few examples:
Cotton is a very thirsty crop, meaning that it consumes a lot of water and fertilizers. For example, producing a pair of jeans needs on average 10 000 liters of water. That is the amount of water a human consumes in 10 years.
Leather comes from hides from animals, meaning that it is natural. However it can have a great impact on deforestation and chemicals release. However, a good leather product is also long lasting and doesn't need to be replaced often, limiting waste, unlike most plastic/vegan leather alternatives.
Wool and cashmere is made of renewable materials produced naturally by animals. But some practices can lead to animal welfare issues or soil erosion (meaning that the land dries and becomes no longer fertile and suitable for any ecosystems).
Polyester is more energy intensive than other materials, creating more greenhouse gas emissions. It is also made of non renewable materials. Polyester is however easier to recycle.
Viscose is made of wood pulp that undergoes intensive chemical processing. This means it is a renewable material (forests), but if unsustainably managed, viscose can lead to deforestation and thus greenhouse gas emissions.
On a general note, it is best to compare a virgin material with a recycled one or a certified one, as those materials have been produced more carefully, taking into account lots of aspects that go beyond yields. In our Made With Care category, textile products have at least 50% of the materials that are either certified or recycled.
What is also always good to avoid are garments with blends. For example a T-shirt that is 55% cotton, 25% Polyester, 20% Acrylic. Blends not only affect the quality of the material and the garment and therefore it’s lifetime, but also make it very hard to be recycled.