If you can diversify your diet every day, you don't need multivitamins. The reason why I see many people taking multivitamins every day is because it is really troublesome to make fitness meals, and the calories have to be calculated for many days every day or once. People are easy to be lazy, so most people cook the same food every day, which is convenient to make and easy to calculate calories, but this will lead to a single food intake, so they will take multivitamins.

If you have enough time to cook many dishes by yourself, and you like different combinations of fitness meals, and you can calculate calories well, then your nutritional intake is very balanced, so there is no need to take multivitamins.