How are points won or loss determined?


The rating increase/decrease does not include accuracy. Chess.com uses the Glicko system to determine rating. The rating difference is only based on a win/draw/loss, and then the following characteristics:
1. The difference in rating between you and your opponent
2. How confident we are of your rating
3. How confident we are of your opponent’s rating
Here's the official support article about this: https://support.chess.com/article/210-how-do-ratings-work-on-chess-com
All wins are considered equal when it comes to rating gain, and the same applies when it comes to rating losses.
Playing a brilliancy in a game is treated as the same as winning a game on time just because you have a pawn surviving on the board against a large army of pieces.