Harder Challenges Post-Netherite

With netherite tools and armor being added to the game, it makes you practically unstoppable, which is why I think there should be a new boss added that when killed, opens some sort of gate to some new challenges. This could come in the form of a bedrock portal that opens up when defeated, or ot just transforms your already existing world. If it was a portal, then it would lead you to a dimension where mobs stand a chance. Itd balance out netherite, to make it much more of a challenge for those who are up for it. It would also be really cool to see new bosses there, as there's only two right now. If it transforms an already existing world, new enemies would spawn and maybe it would generate structures for the new bosses to spawn in. (Like the Elder Guardian)

It would make you feel progression, especially if the bosses and/or enemies had some sort of exclusive reward. Right now, there isnt a structure or boss that really gives you any reward that you cant obtain otherwise. Elder Guardian drops a wet sponge, only to make a sponge. Ender Dragon drops a trophy, not that useful. Ravager drops a saddle, you can get that from dungeon chests. Bastions have good loot, but you can get it in many other ways. Jungle temple is fun, but doesn't give much reward. The only things that are really worth it are end cities and the Wither. Elytra and beacon really help, and give you a real reward. Itd be nice to have something rewarding, to progress. Hope this gets implemented, thanks for reading.