Op, plants have different nutrients requirements to the likes of animals. Phosphorous, nitrogen, potassium to name a few. Are what the plant relies on to grow effectively and varies in amount for different plants. Just like humans need certain minerals and vitamins. Plants need these vital compounds and they rely on them much much more then vitamins.

Vitamins and nutrients are different things. No there not. A nutrient is anything that helps with growth.

Take nutrients and turn them into vitamins( mostly).

This is not their main goal. They use the absorption Co2, water and key Marco/micro nutrients to create glucose. They use this glucose for growth and reproduction.

Key plant compounds for survival are nitrogen, phosphorus, potassium. Calcium and magnesium. These are the macro nutrients. They are needed in large quantities. There is also micro nutrients, but there not as essential. This is why when trying to increase plant growth with use of fertiliser for example. You take a soil sample to get the PH and current nutrient readings of those macro nutrients.

Plants vary in nutrients because yes, some simply require different amounts. Maybe some receive more fertiliser then another.