Most games with 3rd person combat have enemies with slow reactable attacks, and player characters with very quick unreactable attacks, such as Ocarina of Time, Devil May Cry, God of War, Batman Arkham, Witcher, and so on. The Soulsborne series made a bold decision with regards to this. The standard attack speed of most weapons is roughly the same speed as enemy attacks. This means that attacking after an enemy does generally means they’ll hit you first, interrupting you, unlike other series where your attack will come out first. This means you can no longer react to an enemy’s windup with an attack of your own.
By slowing down your attacks, the souls games put you on the same timescale as enemies. Enemies need to be slow so you can react to their attacks and defend against them, and slowing down your attacks to match theirs means there’s more of a risk that they’ll interrupt you before you interrupt them. This means that enemies can afford to rely on hitstun less to be threatening. Overall, it creates more of a neutral game between you and your opponents, where you jockey for position and try to use attacks strategically. Because you’re less sure to hit first, whiff punishing becomes more important to safely hitting enemies.
Slowing down attacks also means that attacks could be more diverse in the time at which they hit, and thereby exhibit a wider range of tradeoffs between damage, range, and speed, which Dark Souls leveraged to create a diverse assortment of weapons. Nioh then leveraged this further by attaching a bunch of moves to the same weapon, and finding ways to distinguish them all using the stance system.
There isn’t a lot to say about this. Slowing down attacks while keeping your defensive options fast is a simple effective trick for emphasizing more of the neutral game in any game with 3rd person combat. It makes individual enemies more threatening, and multiple enemy fights more dynamic too. Obviously not every game should work this way, but it’s cool in the games that use it.