One of the greatest feeling on a game of chess, is sacrificing your Queen on purpose so that once your opponent captures it, you deliver a devastating tactic to win the game. Of course, we don't want to typically give our Queen away but we must be prepared for anything if it means winning the game.
A queen sacrifice is always worth it if you can force checkmate. Sometimes it's also worthwhile if you have good compensation in the form of other well-coordinated pieces.
In this position, white seems hopeless not only because he's down a lot of material but also because he's getting checkmated in the next move with Queen to g2 but, there's still hope for white... can you see it?
All the other pieces other than the Queen can't move, so white can use that in his favor to reach a stalemate by forcing black to take his only piece with legal moves available...
Queen to f8 forces either the King or the Rook to take the Queen, leaving white with no legal moves, making this game a stalemate.