Venus kinda gets the short end of the stick in this episode. Her solo screentime is shorter than the other girls, she is not given any time to be mourned, and her death being placed right before Sailor Mars’ epic final battle does not help.
That said, Venus’ achievements are no less great than the others:
1. Timely push Sailor Moon out of danger: Try to imagine a universe where Venus reacts only a couple of moments slower than she does in here. The Dark Kingdom would certainly have won, as Sailor Moon would be captured and will either be killed or surrender. Which brings us to the next scene....
2. Remind a grief-stricken Sailor Moon not to surrender: When Venus says she won’t forgive Sailor Moon, she really means it. The Senshi have struggled so much, have sacrificed so much to get to this point, and Sailor Moon wants to throw all that away? Nothing would make Venus allow that to happen, not even her own life.
On top of that, (credit to @keyofjetwolf and @paksenarrion-reader over this post) Venus is using Sailor Moon’s own word to scream at her: “yurusenai”. The same word that Sailor Moon says in almost every episode to monsters, right before battle. If this scene cannot convince you that Venus is deadly serious in battle, I’m afraid nothing else will.
3. The final Crescent Beam: I would rank this moment up top in terms of intensity. Other attacks may be more powerful or flashy, but none of them have been shown to knock every trace of prettiness off the opponent’s face.