As they say, "In cosmos near earth but beyond atmosphere there are too much dangerous and powerful radiation frm quasars or gammy burst .,etc". So if there is so much cosmic radiations being emitted, why can't we extract energy from them?
We could, but there isn't enough energy to make it worthwhile. These types of radiation are referred to as "highly energetic" because each individual particle (or very short burst) has comparatively much energy, but averaged over time, there is far more energy around in the form of sunlight. The highly energetic radiation is more dangerous because even a single particle can damage human cells, and over the years it would take to go to Mars (for instance) there would be a considerable risk of cancer. Even then, most of that radiation comes from the Sun.
As a loose analogy, consider the difference between being constantly blown by a steady wind (OK for energy generation, not dangerous) versus being hit by a bullet once a year (useless for energy generation, but deadly).
Quasars are not near the Earth. The nearest one is 600 million light years away. Most are much much further.
They are so very far away that they appear very dim. The brightest quasar is only visible with a telescope, where it appears like a dim star.
The total amount of energy from a quasar per square metre on Earth is minute. It is not a sensible source of energy. Quasars are just too far away.