The issue lies exactly with the menial tasks. Ever used Ansible? It's hell. Not because it's hard, but because there's basicially no debugging and so much hidden state. You're lucky if you can use Terraform, but that's not the default. Depending on the stack, DevOps is mainly just trial and error, "getting shit to work", which depending on the Software used can take a while. And then being responsible for the part of infra you got working, which may necessitate unpaid overtime in case of an outage.

EDIT: One thing I forgot is, that in order to be really good at DevOps, you need to know your stack _really_ well, which imo necessitates that you spent at least some time on the development side of things. This goes against every hiring managers instinct though, as people should only specialize in one thing and do it well (at least where I live).