Why should matter have a high temperature in the depths of stars?

There are two reasons: a) a high temperature is necessary to ensure a high gas pressure, without which the collapse of the star will occur; b) thermonuclear reactions are possible only at very high temperatures.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.