it soaks up many times it’s own weight in water. It then releases it slowly. Perlite is another
In the video, he states that the CEC of vermiculite is 100 times as high as it is for perlite.
The point of vermiculite and humus isn't just to hold water. Nutrients attach to those materials. Without a high CEC material, nutrients will be washed by water down to a level lower than the roots can reach. Humus (and apparently vermiculite according to this video) attract and capture the nutrients. Not in this video, but something I've learned elsewhere is that the nutrients get attached to these materials with a stronger bond than water will break. The plants will pull in water through their roots, but there will be very little nutrients in the water that they take in. The nutrients don't just dissolve into the water. The molecular bonds with the high-CEC material are too strong.
Many microbes have a symbiotic relationship with plants. The microbes are able to break those bonds of the nutrients from the material in the soil. They feed the nutrients to the roots of the plants in exchange for sugars which the plants produce. The sugars provide the energy for the microbes to thrive.
A no-till garden has a high amount of humus in the soil. That humus will capture a lot of nutrients. Not just the main three found in most commercial fertilizers, but also a lot of micro-nutrients that then find their way into the vegetables you harvest from the garden. The nutritious minerals from a no-till home garden are bound to be significantly higher than found in produce from large-scale farms producing food for the mass market.
I believe it is best to avoid using fertilizer for the most part. The nitrogen will burn up the humus if present in too large amounts. That allows the nutrients to leach away, whether the nutrients come from store-bought fertilizers, or from decaying insects, worms, fungi, microbes, and dead plant matter. In addition, a lot of fertilizers are harmful to the microbes in the soil that do the work of breaking the nutrients free from whatever they're attached to.