The reality is that most devs do not consider a holistic picture that includes the infrastructure they will be deploying to. In many cases, it's certainly a skill issue; good devs are hard to find. And to flip the coin, it's hard to find good ops people too.
The reason DevOps continues to linger, however vague a discipline it is, is because it allows the business to differentiate between revenue generating roles and cost center roles. You want your dev resources to prioritize feature work, at the beckon of PMs or upper management, and let your "DevOps" resources to be responsible for actually getting the product deployed.
In essence, it's a ploy to further commoditize engineering roles, because finding unicorns that understand the picture top-to-bottom is difficult (finding /top/ talent is difficult!). In this way, DevOps is well and alive, as a Romero zombie.
Remove the handcuffs from your ops team and your reliability will SOAR.
Kubernetes deployment configurations and Ansible playbooks are code. PromQL is code. Dockerfiles and cloud-init scripts are code. Terraform HCL is code.
It’s all code I personally hate writing, but that doesn’t make it less valid “software development” than (say) writing React code.
There is also a subset that is very allergic to coding at this point. I've interviewed enough to see people who only know HCL/yaml. There is enough need and work (waste?) in the space that roles like this can exist