I love the ancestral foods subject! A few reasons some concentrated whole foods supplements (rather than lab processed isolated compounds) are often needed regardless if one is or isn’t “carnivore” or “paleo-keto”:
*Industrial agriculture has depleted topsoil (desertification demineralizes soil, and plants & animals who eat the plants continue that chain of demineralization - esp magnesium). In addition, the overwashing of veggies and/or cooking of them rids them of beneficial microbes that traditional farmers and gatherers used to get by snacking on hand-picked fresh leaves, roots, and fruits.
*The average person has at least 100 industrial chemicals in their blood/organs and breathes daily indoor and outdoor pollution - that’s quite a load of toxins which are taxing to the body and which our ancestors didn’t have to deal with on top of basic food supply. Detoxing requires high functioning processes that pivot on magnesium and other minerals.
*The average person isn’t exposed to the sun in traditional ways (gazing at the sunrise and sunset), and is an indoors creature. Vit D depletion is rampant, esp in midlife female metabolisms according to keto-obgyn Dr. Anna Cabeca - and Vit D affects how minerals are used in the body.
*Modern culture is very stressful for most folks - in ways that our stone age nervous systems and hind brains aren’t suited for. Stress burns up B vitamins and boosts cortisol. Though a great food source of calming B vits is organ meat/offal - most ketoers don’t eat it regularly or at all - unlike our ancestors, who often made soups with fish heads, and treated liver & kidneys as preferred delicacies. So taking it in capsule form can be good for self-care.
*Modern people in industrial culture have had tons of gut disruption from frequent antibiotics and processed foods. Restoring healthy gut bacteria populations via pre and probiotics throughout the 25-30 feet of intestines takes around 3 years according to many experts I’ve read. Our ancestors ate live-fermented seaweed, live-fermented birds and eggs, live-fermented raw yogurt/kefir, live-fermented cabbage, live-fermented mushrooms, and such. If one isn’t making their own live-fermented foods, it can help to supplement with a pro-enzyme like Ginger, or with serious heavy duty prebiotics like SBOs - soil-based organisms.
So, whole foods supplementation can be very helpful for healing - preferably from natural sources like some of the above mentioned food sources. The only commercial supplements I take are weekly D3 (lanolin-based, during months of minimal sun exposure due to intense heat), angstrom mag several times a week, nascent iodine when I’m not eating much seafood/seaweed, and an adaptogen like Ginger (Turmeric is also great, but often more expensive) in capsule form with every meal that doesn’t contain it in my cooking - simply because I’ve not yet gotten around to making my own Ginger pellets. Oh! And I also “supplement” with liver capsules several times a week, because I’ve still not gotten round to eating liver/offal…
I don’t trust most lab-isolated supplements and multivits - though I know that all the LCHF/keto physicians generally recommend high quality artificially created ones. I’m more a fan of whole foods concentrated sources (esp superfoods like Ginger, Moringa, Turmeric - along with raw goat milk when it can be found), and I try to aim to get nutrient density through quality pastured whole foods whenever possible. 
Considering that most of the world’s population deals with food scarcity and malnourishment though, it’s really a very privileged thing to be able to even ponder supplements on top of a nutrient-dense LCHF way of eating though, that’s a salty fact.