I use to believe pellet food was not important. I didn't feed my rabbits pellets for about 4 years. However, when one of mine got bladder stones/sludge, I changed my stance. When my rabbits didn't get pellets, they got a lot of veggies and a good variety. However, I think my rabbits were still missing minerals and vitamins. I now offer pellets but a small amount. They get 1 ounce twice a week. I still feed lots of veggies and I feel like the pellets will fill in any missing minerals or vitamins they are not getting from veggies and hay. I also feed a variety of different kinds of hay. Am I 100% sure that they do need pellets? No, but I feel more comfortable feeding them to fill in with anything they are missing. I think may be I could alter a veggie diet to be a wider variety to give more minerals and vitamins, but I am not comfortable with my level of knowledge to be sure they are getting what they need so I supplement with pellets.