Agree with other commenters here in that writing it and sharing it is important, but probably everyone in that list will agree with what you say about the others, but completely shrug off whatever is aimed at themselves.
One useful place for that letter might be in using it as a public reply everytime they message you or mention you online, so others might be able to take it as a warning or validation for their own interactions with them, but as a direct hit on their ego it will just be met with deflection and justification. At minimum it might make them avoid you instead of you having to avoid them online.
Agree with other commenters here in that writing it and sharing it is important, but probably everyone in that list will agree with what you say about the others, but completely shrug off whatever is aimed at themselves.
One useful place for that letter might be in using it as a public reply everytime they message you or mention you online, so others might be able to take it as a warning or validation for their own interactions with them, but as a direct hit on their ego it will just be met with deflection and justification. At minimum it might make them avoid you instead of you having to avoid them online.