WARNING: The following contains spoilers for Boruto: Naruto Next Generations Episode 181, "The Vessel," now streaming on Crunchyroll, as well as for manga chapters not yet adapted to the anime.
One of the biggest surprises in the Boruto series has been Sasuke advocating for the use of scientific ninja weapons. Naruto's son couldn't understand his sensei using them in battle against the Purple Moon cult, especially as Sasuke has so many weapons naturally in his ninja arsenal, like the Sharingan and Rinnegan eyes.
In fact, he felt Sasuke would disapprove of them, especially after Boruto used them to cheat in the ninja exams. But Sasuke admits that, once used right, they're a sign of progress and the dreams so many Hokage of old envisioned. Now, in Episode 181 of the Boruto anime, the Uchiha Ranger reveals another secret as to why they should be incorporated into a ninja's strategies for the battlefield.
Boruto's upset his dad used a prosthetic arm in their sparring session that could absorb all his moves, thinking that he's a hypocrite. Naruto reprimanded him for cheating back then, so Boruto can't tolerate what he feel is a double standard. He already despises these tools as they reminds him of his lowest moment. Seeing his father using them is just salt in the wound.
But Sasuke comes to Naruto's defense, telling Boruto these weapons add a necessary element of surprise, something crucial to a shinobi's strategy. Sasuke's eyes and Kurama (the Nine-Tailed Fox) are what gave warriors like him and Naruto the edge respectively, and as Kakashi taught them, if a shinobi can shock an enemy using a new tactic, they need to use it. Sasuke tells Boruto if the tools are there, just like how medicine can help patch them up outside of chakra use, it needs to be integrated, but smartly.
He reminds the kid how ninja usually focus on one aspect of the battle: the techniques that are expected. It's why Naruto absorbing all Boruto's moves rendered him useless, proving just how much the element and art of surprise can be a decisive factor. Boruto was simply waiting on shadow clones and the Rasengan so, when the arm was used, he simply had no response and shut down. More so, these tools allow them to use different states of nature.
Boruto used wind, water and lightning, but he had to learn and practice a lot over the last few months. Sasuke adds that this is most welcomed but for him, as he specializes in lightning and didn't have time to perfect water, when he used water bombs against enemies in the past, they didn't expect it. It's convenient for him, makes him unreadable and in his view, it helps Konoha's soldiers evolve, using science to balance their natural skill. In other words, it's not just about making up for shortcomings, but about throwing the enemy off to protect the Leaf Village.