A nether and end added would bring a lot of players to POC, Say if someone lights a portal they tp to the nether (A huge flat world but generated with lava and netherite and all the mobs,like you did with onlinr creative) And everyone is able to build . Strongholds can be generated and with the nether people can kill enderators for pearls and blazes for powder to make the eye of ender to find one and go to the end. The end can be a private map with no way out except killing the dragon,and for entering and exiting both dimensions their stuff can be saved,another portal can appear after the dragon dies to the end city,private map with end cities,fruit and ships
I feel like this is a lot of work yes it may bring new players but old players may quit because it is just too different. Adding all of this for this game would take years and would lag the game out soo much. Also if they add all of this it may be enough to sue this company for copying Minecraft. I do like this idea but it's quite a lot and other people want other things more.