How is this a blunder?

I cannot for the life of me figure out why the engine considers this a blunder (took a rook on A1 obviously) help would be appreciated

The analysis show what white’s best continuation is. The knight in c6 is hanging, so you will likely lose two minors for a rook and pawn, which is normally bad. There are likely additional positional considerations, such as dark square weaknesses, depending on the line.

Because gaining the rook cost you two pieces - a knight on c6 then a bishop on either b7 or a1.

Now that you've taken the rook, white is going to take your knight next, then you have a choice of which bishop you are going to move, and you'll lose the other one.... 2 pieces for a rook.