For me, it will be if they ever get checked errors of some sort. I don’t want to use a language with unchecked exceptions flying about everywhere. This isn't saying I want checked exceptions either, but I think if they get proper unions and then have some sort of error union type it would go a long way.
You can get an error union now: https://github.com/amantinband/error-or
The issue is the ecosystem and standard library. They still will be throwing unchecked exceptions everywhere