I think that part was made up. Apparently the chair was never even there when the Hodgesons moved in! I think they just referred to the position of the chair 'in the corner' - and James Wan decided to elaborate on that element. It was True that in those days in council houses where people couldn't afford much furniture, things would get left and past down from one tennent to the next!
I was thinking that at the end too and it really confused me that they didn't. The way the film made it look, the chair was the haunted object and not the musical, moving image thing.
The zoetrope toy was haunted, a couple of times the Crooked Man figure disappeared from it then turned into the full-size horror. It was probably created by Valak.
Also the belief that ghosts can be attached to objects or furniture which had some significance to them - like a chair he died in - has been around for a long time. Once the situation became news you would have thought that the family would have been told that, by several people, and if they wanted to get rid of the ghost they would at least have sacrificed that one chair in hopes it would do the deed. It's not as if it was the only chair in their living room...
(Is not supposed to work with poltergeists which are believed to be rather attached to a person, usually a young teenager, but still, with that kind of disturbances anybody normal should have at least tried.)
In real life the "ghost" did say (through Janet ) that he died in the chair in the living room. But that doesn't mean it was the exact same chair.
And i highly doubt Peggy actually died in the same chair. I've never heard that anywhere but this movie. In real life the chair was probably thrown away after Bill died in it. I remember in the 2015 Sky Living Tv mini series, The Enfield Haunting, the old mans son saying : "I doubt its the same chair mate. Unless its had a good shampoo " :)
history is a battle fought by a great evil,struggling to crush a small kernel of human kindness
Yes, but I am not talking about the real story, just of the logic of this movie. That bit did make the characters, including the Warrens, seems a bit lacking, I wished it would have at least been brought up. Considering the time frame of the story the Warrens could well have mentioned it after they arrived, but then things escalated so fast that they wouldn't just have had time to actually do it.
And of course no real point to do it afterwards since Bill the ghost presumably moved on once the demon was gone, or if he didn't all by himself he was presumably a rather harmless ghost. (My impression was that the demon had probably been controlling him from the beginning, the family had been living in the house for a while but nothing happened even thought the ghost presumably had been there the whole time. Then the girl plays with the Ouija board and presumably gets noticed by the demon, and only then Bill starts haunting them).