It's good but, due to the early complications with the bishop, there are so many more 4th moves white can respond with, which you wouldn't typically see otherwise - a3, Qb3, Qc2, Bd2, f3... and different combinations of these moves as well. It ends up being a very broad move tree... in addition it's also such a critical line, and people study it relentlessly. White has alot of choice in where the game goes. So I'm afraid it's just too much theory for me to go for. However... besides that it gives black great initiative, it plays very naturally, and it's a great line. And black has many options too, so that kind of makes up for things... kind of. I wouldn't really want to play such a theoretical line intuitively when my opponent is steering the game, though.
Also the thing it naturally pairs with, the QID, has a similar problem - huge amount of theory due to ceding the center.
Maybe if I was a pro chess player I wouldn't mind these things.
The other thing is I really like the English Attack against d4/c4, I think I'd just choose it over the nimzo.
One of the earliest known players of the unique 3... Bb4 move (which didn't yet have a name) was the British master Joseph Blackburne, one of the top players in the world in the late 1800s. Blackburne was known among players as the "Black Death", due to how dominating and ruthless his play was.
But it wasn't until the 1920s that Aron Nimzowitsch came along and made 3... Bb4 his trademark, cementing the "Nimzo-Indian Defense" as a permanent cornerstone in chess theory and history. His idea was simple but revolutionary: attack the center with pieces, instead of occupying it with pawns - a big departure from the Classical way of thinking at the time.
According to Nimzowitsch, the point of the bishop move wasn't simply to pin the knight - it was actually meant to indirectly fight for control of the e4 square. The birth of Hypermodernism.
Since then, the Nimzo-Indian has been a favorite of World Champions such as Capablanca, Kasparov, and Carlsen. In fact, it would probably be hard to find a single World Champion who hasn't studied and played the Nimzo-Indian, at some point.
So ... where do you stand on the Nimzo? Do you enjoy it as Black, and have a favorite variation? Hate it as White, and employ different moves to avoid it? Or do you know little about it, and would like to learn more?
Let's talk about the Nimzo ...