My own instructor, Soo Young Cha, was Korean. In the early '50s he and General Choi set out on a program to train and toughen up the Korean Army. Eventually, every Korean army officer was to be required to have a black belt. They devised a new system of martial arts. They began with Sho Shin Do which was an older form of Korean Karate. Cha went throughout Asia to study with the great masters, including Oyama of Japan. He brought back the best from various places then he and General Choi created Tae Kwan Do. At that point in one year Mr. Cha won the Korean, Taiwan, Tokyo, Okinawan, and a few other places Karate championships, becoming all-Asian champion. What you obtain at top levels is a synthesis in the best people.
Cha had his opinions. He discouraged study of areas such as nunchucks in his students, saying if your Tae Kwan Do was good, you didn't need such trivial items. That's easy to say when you are an 8th or 9th degree black belt.
In Korea he once had three guys attack him with guns in an attempt to kill him. Before thay could pull the triggers he disarmed them and knocked them on their asses.
He was know for his air break. You could throw concrete blocks in the air and he would shatter them with a judo chop. The means concrete, not porous cinder block. When it was captured on film it looked like they were being hit with a 30-06. He'd do the same with regular small ceramic building block. I had a picture of him shattering stacks of concrete and thick roofing tiles with his head. It looked like the stuff was being hit by a cannon.
But we all age. For a while during the 80s he was afflected with a severe kidney ailment. There is no way he could do what he once did. Neither can Steven Seagal. He will find that out.
Those type skills require a certain youth, and constant training, while the relaxed and reactive circular parrying and locking and throwing styles like Aikido are effective years after training, even when older. They become relexive, so that an unexpected attack (a sucker punch) is dealt with from deep instinctive memory without warming up, stretching, getting into a stance and so on.
Plus, against mulitple opponents, Aikido is much less energy draining. High output styles like TKD leave one quickly exhausted when facing multiple opponents who are cagey in their attacks.
Just MHO, your mileage may vary.