Really depends on the game, story and pacing. But I think both are good. You want a final boss as a a climax to the game. But the victory lap is a nice way to end the story on a nice note and wrap up all the lose ends in the story and give closer.I hate prologues except for tlou and mgsv. Just let me play the game!
Again, it really depends. I also like prologues, but don't make them too long. The one in RDR2 for example was waaaaaayyyy too long
Do you have any final bosses/victory laps you really liked?