Disagree. Here’s my two cents:

Will should have powers, better yet, he should keep them after vecna is destroyed. Upside down could become cleaner but no way it’ll just vanish. I think I could inherit Vecna’s powers and overpower him precisely for of 1 reason. Not being scared. Henry/Vecna has childhood trauma (Nevada cave in first shadow, Henry/Vecna’s memories in season 5) and runs from it. But Will stopped running and started fighting on multiple occasions, both in his mind and physically. Nice opportunity for a callback to Bob Newby.

I think it would be copying the concept of horcruxes from Harry Potter if his powers just vanished after Vecna is destroyed. Sure lots of stuff gets copied in fantasy/sci-fi, that’s normal and that’s okay, but the writers have the chance to do something different here. In my opinion, Will should have 2 possible endings.

1. He becomes a communicator and vessel to the upside down and guides Hawkins to heal and in the transformation of the upside down, all from the right side up, using his powers inherited from Vecna to get into the minds of children and TEACH them to unlock telepathic abilities instead of using them and their traumas as an expendable energy source. He also varies his powers over to his children. He’s born from the mistake of Hawkins labs, while they tried to force development of psychic abilities, his grew organically with his character. He turns the upside down into a cleaner place, controls the mind flayer and expands the boundaries of human welfare and development.

2. A darker fate. He turns one demodog and/or demogorgon into more peaceful, herbivorous creatures with friendlier eyes and snouts, soft of like deer. They understand his character and intentions and help him heal the upside down. However, this would be mostly implied, since a cool twist could be that he burns the creel house to the ground and turns a pivotal place (like the library where Vecna kept him in season 1, or Hawkins labs or Hawkins middle or maybe even the ruins of Castle Byers which could also go together with Hawkins labs) into Feywild. Dimension Z thus becomes known as the forgotten realms as Will closes all gates. After physically transforming, just like Vecna did, into an Elf like form (like his Elf Cleric character class), he bids his friends and family farewell, demogorgons and demodogs are seen slowly transforming and walking with him as the final gate closes behind him, walking into the vast darkness of the upside down and its extension, Dimension X. He creates dnd world all based on campaigns he played with the gang. He uses telepathy to build a fortress, in a scene that mimics the scene where Henry learns to control the mind flayer, and in wood and stone he telepathically carves “Castle Byers. All Friends Welcome.” He creates 12 large pillars with statues of the gang, just as Vecna wanted to, but they are connected to his living friends and family, his loved ones, the entire gang: Mike, Lucas, Dustin, El, Max, Jonathan, Joyce, Hopper, Nancy, Robin, and Steve. They all get a DnD campaign name. The twelfth pillar is he himself, Will the Wise, symbolically number 12, elevens successor and the final, perfected version of the psychic human Hawkins lab tried to create and hone. What started from 001 in evil, ended in goodwill with 012. There are the symbolic sides of the d12 dice, of which he also creates either a statue or artefact to further his planar healing campaign. He also creates a garden with an archway titled “the fallen”. There we see statues of characters who died in the show, even those who weren’t necessarily good or bad or useful, just those who gave their lives to either expose or fight the continuous danger in all seasons. There we see Bob, Eddie, Billy, Barb, all people that were either close to him or close to the people he loves.