AIKIDO is popular martioal arts devepoled by Morihei Ueshiba in Japan. Now it is popular all over the world from child to adult.
Is AIKIDO useful for real fighting?
This answer is half Yes and half No depending on a way of exercising.
If you exercise hard simulating real fight situation. For example, sparing with boxer or wrestler. In a sparing, some techniques are useful , on the other hand some are not useful. So you must consider why the technique is not useful, and fix the technique to be useful in KATA trainig.
Therefore, exercise partner need to grasp as hard as possible. Otherwise AIKIDO is not useful on a real fight grasping heavy power.
Of course, KATA taring is imprtant to learn basic formula. Exercise partenr need not to grasp hard.
If you exercise KATA trainig only. You can not fight with enemy in a real fight. But only KATA taining is not useless. Breaking fall exercise is very useful to keep you from injuries. Breaking fall is effective for other sports especially having hard physical contact for example foot ball , rugby football.
You must simulate a real fighting in a exercise. And AIKIDO is useful. In fact AIKIDO is intrduced army. No sparing is weak point in AIKIDO, so you must spar with other martial arts player.
Children should start AIKIDO or JUDO to protect them from injuruies. For example, slipping on a road or dropping from a horse or falling over on skiing, daily life has lots of risks for active children.