Why are entry requirements for BTEC students so high compared to A levels?

I don't follow really. Why would you be expected to have an A Level in Maths if you are doing a BTEC? That doesn't make sense.

Im looking for universities to study computer science, and i have noted in a lot of the top 25 universities, they have entry requirements like say for example AAB or AAA with an A in mathematics. But for the BTEC level 3 extended diploma its D*D*D with an A in a level maths? why is this? a btec level 3 extended diploma is equivelent to 3 a levels so that along with a level math would be eqwuivelent to 4 a levels, so shouldnt the BTEC requirement be lower? kinda unfair ngl

I don't follow really. Why would you be expected to have an A Level in Maths if you are doing a BTEC? That doesn't make sense.

Because such courses are highly academic whereas BTec are seen as more practical.