Dungeon Running (Bosses, not just chest and spawner)

   Now this may be inspiration from several games, I feel dungeons are highly overrated, it's literally a chest or 2 and a spawner. Now sure, these can be used for XP farms, but after you find 1 or 2, now what? After you find a couple, they're just chests, and if u get a decent fishing pole and afk a little bit, whats the point of going out and looking for dungeons for nametags? After a few hours of a world in Minecraft, dungeons are no longer needed. I feel this is a good way to make them possibly underrated, and if you play a multiplayer world or server, this is even better, and easier. 

   My suggestion for this particular section of Minecraft is Dungeons. We need to upgrade them. So what I'm suggesting is this: That first, dungeons have a spiral staircase going down, with actual staircases. At the end of this staircase you would have a broad hall, leading to a portal at the end of the hall. Once entering this, there is no exiting it until you defeat the boss. Now the boss depends on the dungeon. Skelly dungeons would have a lich. Spider dungeons would have a spider 10 blocks high, and zombie dungeons would have an undead boss. Now in multiplayer worlds, dungeons would be harder, and you can have a group of up to 5, depending on how many members are in group, the difficulty increases, 1 player - 100hp, 2 players - 250hp, 3 players - 400hp, 4 players - 500hp, 5 players - 1,000hp. Now different dungeons will have a different interior. Spider dungeons will have the giant spider, webs, redstone, which is way to dark for Minecraft, I know, and spiders everywhere, cave spiders and regular. Skeleton Dungeon will have a bunch of fossils, skeletons, Lich, green ponds of water, like, a swampy, brown, disgusting green. It will also have skelly heads, and the murky fountains coming in from all sides, and little drains here and there, kind of like a sunken underwater temple, inspired a little by the World of Warcraft dungeon, Sunken Temple. The Zombie Dungeon will be an underground city, undead everywhere, and a huge troll/ogre/undead boss at the end of it. I feel dungeons should be a different aspect of Minecraft, sure, The End is the end, but dungeons should be something after, because the Ender Dragon fight isn't really terribly hard, and that's the end of it? I feel there should be a dragon, like Onyxia in WoW, an endgame fight, though WoW continues, but I won't get into that, and so will Minecraft, but the dragon will be huge, bigger than the Ender Dragon, and can blind you, put you to sleep, knock you back, have Dragon's Breath, slow you down, shoot bombs that erupt fire, and put an effect on you where you can not heal for 10 sec. It will have 2,500hp, a regular hit will do 20hp damage, the dragon is arrow-proof, potion-proof, trident proof, and can not be hit with any other weapon than a gold sword, because dragons are vulnerable to that kind of stuff. I'm sorry this was kind of about a mob, too, but the main theme is I think we need better dungeons, that's long overdue.