The thing to know about Vitamin A is that there are two different versions.
Active (retinoid): Readily available from dietary consumption.
Precursor (carotenoid) : Requires the bodies ability to convert into active form.
Vegetables such as carrots are thought to be high in vitamin A. This only true in they contain the caroteniod called beta carotene. This gives vegetables the color but also contain the precursor to vitamin A. The body must convert this into useful vitamin A. ("about 45% of people carry a genetic mutation that significantly reduces their ability to convert pro vitamin A into vitamin A")
Animal-sourced food contain the active and bio-available vitamin A (retinol). Making them better sources of Vitamin A.
Beef Liver is a good example of being a greater source of Vitamin A than carrots.
Sources:
https://en.wikipedia.org/wiki/Retinol#Nutrition
https://www.healthline.com/nutrition/foods-high-in-vitamin-a#section2