What are the merits of Anand's exchange sacrifice in game 9 of 1995 World Chess Championship? From various sources (some of which I have mentioned below) I have heard Vishy Anand's 27th move in game 9 of 1995 world chess championship match against Gary Kasparov , which was an exchange sacrifice is considered to be one of his greatest moves.



Link to the game.

Kasparov accepted the sacrifice, but had to resign game  8 moves later.

Obviously due to my incompetence, I fail to see the merit of the move.
I checked with engines, neither stockfish is recommending the move nor engine is giving any significant improvement in evaluation of the position in favour of white after the move compared to before the move.

What are the merits of this move?

What improvements does this move bring for white?

Sources:


Anand's new book "Mind Master" mentions this game and the move. (I have not read book)
Chessbase India has a series of YouTube videos asking different top grandmasters to guess some of Anand's famous moves by showing the position.
This game and position is featured there in the videos.
Link to Magnus Carlsen's video is here and this position is discussed around time 1:10
Popular Chess YouTube channel of Agadmator covers this game and infact this position is the thumbnail of the video. But still don't explain why this move is important or how it improves things for white.
Well, the obvious answer is that taking it leaves white with two connected passers (possibly after a future a6). That is incredibly strong since they control so many central squares, and threaten to advance strongly at any moment. This keeps the opponent tied down, and constantly worried about their advance.

I once saw Joel Benjamin sac a whole piece just for connected passers on the 5th. I think it was at the 1985 World open versus Sandeep Joshi, a prodigy at the time. It has been a long time, but they were so strong, i don't think that he never moved them.

Frankly, the other point behind it is that white is going to double rooks. Kasparov was wrong, at least practically, to take. In his notes to the game, Anand give Nxd5 two question marks, and recommends waiting with 27...h5.