This comment is as far from true as the decision is far from trivial. That is to say, very far.

By far the second most common piece to promote to is a knight, simply because a knight moves in a way a queen cannot. In my 10 years of playing chess, I have probably seen about 5-10 tournament games where promoting to a knight is the correct choice.

Here is a FEN of an example where the only saving move for Black is to play 1...e1=N+: "8/8/8/8/8/3K4/R3p3/3k4 b - - 0 1"

You are right in that the only reason to ever promote to a bishop or rook is to avoid stalemate, yet there is only one practical example of such, here: "8/2P5/8/8/3r4/8/2K5/k7 w - - 0 1".

White must promote to a rook, since if they promote to a queen Black will play 1...Rc4+, forcing 2...Qxc4, which is stalemate. I cannot even find a practical example of when promoting to a bishop would the best choice.