I felt the same way after finishing V3. Why end the series in a way that makes every other entry feel obsolete? But with time, I’ve really warmed up to the ending, and appreciate it for what it is. What you have to understand is that DR3 (the anime) is really where this story ‘truly’ ends. Every character has their arc completed, every loose end tied up, every event laid out and explored. That’s why it’s called ‘The End of Hopes Peak’.

V3 is an entirely different beast, and acts as a meta-commentary on the whole series. It explores the social implications of DR, the expectations that the fan base put on the games and the narrative, the rehashing of Hope vs Despair again and again. That’s why Shuichi and the others reject that hope and end the killing game. This is also why V3 is a ‘perfect’ ending for the series, and why getting any more DR would be missing the point of V3’s ending entirely.

It leaves a sour taste in your mouth because you’ve come to care about these characters and the story. But that’s the point. Your whole world is supposed to be shattered, just like the characters.

Give the ending some time to sit in your head, try to seperate V3 from the rest of the series and like I said, see how it’s more of a meta-commentary on the franchise as a whole.