A fair question to put to a supplement brand. The honest answer is: for the most part, yes.
What ordinary food covers
A varied diet with enough vegetables, fruit, wholegrain products and protein sources supplies most people with everything they need, both the macronutrients and the vitamins and minerals.
Supplementation is not a precondition for health. Anyone eating well and varied gets a long way without it.
Where protein becomes awkward
With protein it is not a question of ability, but of organisation. The amounts someone training seriously needs are achievable through food, but require planning and time.
A shake is a practical solution for that. Not because food falls short, but because your day does not always allow it.
Where the real bottlenecks lie
With vitamins and minerals there are a few situations in which diet does not cover it, and those are well documented.
Vitamin D. In the Netherlands we produce too little of it via sunlight for a large part of the year. The Dutch Health Council therefore advises extra vitamin D for certain groups, including women from fifty years of age, men from seventy, people with darker skin and people who spend little time outdoors.
Vitamin B12. This does not occur in a usable form in plant-based food. Anyone eating entirely plant-based needs supplementation. That is not a preference but a necessity.
High training load or a restricted diet. If you train a lot, eat little or leave out entire food groups, the chance of deficiency increases.
On multivitamins
A multivitamin with doses around the recommended daily amount is a low-threshold way for most healthy adults to cover any gaps. It does not replace a varied diet, but it can serve as a safety net.
Do be careful with high doses of individual vitamins and minerals. With some, too much is genuinely harmful: fat-soluble vitamins accumulate in the body, an excess of vitamin A is risky, and iron supplementation without a demonstrated deficiency is not straightforwardly harmless.
The practical rule
Food first. Supplements to fill gaps you cannot close with eating. And if you are unsure about a specific deficiency, have it measured by your doctor rather than guessing.
Sources
Dutch Health Council (Gezondheidsraad). Advice on vitamin D supplementation for at-risk groups in the Netherlands.
Can you get everything from food?
A fair question to put to a supplement brand. Mostly, yes.
For protein it is not a question of whether you can, but of organising it.
Related reading
How much protein per day do you need?
Whey or protein powder: what is the difference?