First> I have never had before a game that takes more than a half hour. It is maybe, because I'm going to die soon. In my experience the game takes only a long time if there are campers in te game.
Second> I have never played skywars on hypixel, but why should the games end faster in Hypixel and take more time on Cubecraft? Hypixel has a chest refill and that takes more time than a chest with only one time loot.
Third> If you like the speed, you can take the kit, scout. It gives you 3 speed potions of lvl 2.
Fourth> Speed skywars isn't a bad idea, but Cubecraft has removed the speed on speed eggwars, because people hate the speed that they had. Yet, the game ends faster in speed eggwars than in eggwars (mostly), because the islands are closer together. What is the conclusion for this problem? You can Join maps with island close to each other. You won't have a game of a half hour (unless that there is a camper in the game).