I'd like to present two ideas to modernize the CS2 reward loop with zero impact on core gameplay.
1) A subtle, satisfying audio cue to accompany the visual card effect at the bottom of the screen.
2) Inspired by tournament replays, a brief timescale slowmo at the final kill of the match. It makes the final moment more fulfilling without affecting the rounds leading up to it.
Sometimes it’s the small, 'useless' details that count.