Judo's initial innovations were not in techniques, but in the manner of training them.
Kano emphasized the use of randori (free practice) in training. This contrasted with many jujutsu schools that focused on kata, or prearranged exercises. The tradeoff is that more dangerous techniques such as striking were removed from randori; these remain in judo kata practice but are not part of randori or shiai (competition). Randori allows development with non-cooperative partners where both partners can adapt and learn.
From Kodokan Judo by Jigaro Kano, published by Kodansha International Ltd., 1986, p. 141:
One reason judo has evolved into an international sport is that its two forms of practice, randori and kata, are ideal ways of training. This was not the case with jujutsu, which was learned almost exclusively through the practice of kata. In those schools that emphasized randori, such as the Kito and Tenshin Shin'yo schools, practice in randori came only after attaining proficiency in kata.
From Judo Memoirs of Jigoro Kano by Brian N. Watson, Trafford, 2014 p.37
When one makes a detailed comparative study of traditional jujutsu with Kodokan judo, big differences between the two system soon become apparent... The essential point of difference though, is mainly in the methods of upsetting the opponent's balance. These tactics are unique to Kodokan judo. No matter what technique is to be applied, only after successfully disturbing the opponent's balance should one pursue one's attack.
This particular principle is kuzushi or off-balancing. Kano took existing techniques and refined them in light of studying kuzushi.
From Kodokan Judo by Jigaro Kano, published by Kodansha International Ltd., 1986, p. 16:
In my youth I studied jujutsu under many eminent masters. Their vast knowledge, the fruit of years of diligent research and rich experience, was of great value to me. At that time, each man presented his art as a collection of techniques. None perceived the guiding principle behind jujutsu. When I encountered differences in the teaching of techniques, I often found myself at a loss to know which was correct. This led me to look for an underlying principle in jujutsu, one that applied when one hit an opponent as well as when one threw him. After a thorough study of the subject, I discerned an all-pervasive principle: to make the most efficient use of mental and physical energy. With this principle in mind, I again reviewed all the methods of attack and defense I had learned, retaining only those that were in accordance with the principle.
Kano believed in the use of judo as physical education, cooperation, character development, and self-perfection. This is departure from the view that martial arts are only about fighting.
One validation of the judo approach was the results of competition between the Kodokan and the Totsuka Jujutsu School.
Also keep in mind that when you encounter jujutsu today, it is not the jujutsu of Kano's time, but influenced by judo. Also from Kodokan Judo, p. 19:
Eventually judo displaced jujutsu in Japan, and no one speaks of jujutsu as a contemporary art in Japan, although the word has survived overseas.