Because the migration has to be auditable. And the data fields between the systems / databases mapped against business processes, on both systems. If you find a solution to automate that, cudos...
No, from my experience it wouldn't be fair to say that.
There is a reason why migration projects are yearlong, multi million projects. Go through one, ideally multiple, of those first before looking at automating any of that. Added benefit, jobs at those projects pay incredibly well for the functional consultants involved. And when, when not if, automation doesn't work out, you still don't have to worry about a job ever again.
