- When an async state would spawn tasks on `actix-rt`. If state was centralized there could be a possibility the tasks get an unbalanced distribution on the workers/threads (`actix-rt` would spawn tasks on local thread whenever it's called)
The real world difference can be vary by the work you are doing but in general it's a good idea to spread your _identical_ async tasks evenly between threads and have as little cross threads synchronization as possible.