Fiber might be valuable for many for various reaons but it is not essential for everyone. For example, I don't get any fiber in keto-carnivore diet for many years and my digestive system and blood markers got much better.

Dr Mason also explained it in a health conference as I attached in my story. I also observed many people cut fiber.

https://medium.com/sensible-biohacking-transhumanism/why-did-i-entirely-cut-fibre-from-my-diet-d81ebfd239c6

https://medium.com/p/778c0e6932fa