You say the Ego is bad, is it not necessary also?

Of course.
The ego never disappears. It is needed in the Sansar.
The ego is a gift of the consciousness, it is part of us.
We can’t just throw it away.
Mind = Maan = Man.
We don’t want to cut off an arm, just because it can kill someone.
Problem is not with the arm.
Problem is with the decision making at the mind level, that needs to improve, and same arm can save many lives.

Science itself is also a gift of consciousness.
But when and how to utilize this Ego, needs wisdom.
True wisdom does not lie in the mind or mind-driven, Ego-driven, Sansar.
To find it, one needs to explore what is beyond the Ego. ( and that is meditation ).
Beyond the Ego, lies the thoughtless state, the vast consciousness, and that’s where one finds the non-dual wisdom. ( Advait ) – your true identity.
Wise use of the Ego can bring wonders, and unwise use, disasters. ( Nuclear energy vs. nuclear Bomb ).
Spiritual path brings that wisdom in your life.
Utilizing Ego to lose your life in consuming objects of pleasure, I would not call it a controlled fire, but acquiring spiritual wisdom IS controlling the fire.
A balanced approach is needed, where Ego remains but is utilized for greater good – man, animals , environment, the universe.
A lopsided approach will lead man to self-destruction, which he is very close to.