Technically, version control lends itself naturally as part of the now well-accepted infrastructure-as-code mantra.
Operationally, version control is the one that developers interfacing most primarily, shifting the interactions to that interface would be benefitical to users.
Of course, DevOps as a skill set is becoming less and less relevant, given the increasingly integrated toolings that interfacing directly with developers, that's for sure.
So, it's a very interesting situation. On one hand, I agree with you: when I start a new project, I am the master of it, I take care of everything and I need to make sure deployment and testing are implemented as early as possible. But this needs to scale. When we hired more people, I quickly realized no one wanted to deal with CI. They wanted it to just work and I wanted people to work on features and bugs, not fighting CI. So you can call me a devops guy by accident (turns out, that's a huge chunk of what I do as a CTO - remove obstacles by implementing and managing devops).
I think my ideal devops situation is the one where you start with a simple deployment script from your local machine when it's a one man show and then scale it to a large organization not by switching to a large piece of devops software, but by gradually adding pieces that you need as your team grows and requirements change. Exactly what happened to us and I think our devops workflow is really great and I'm very proud of it.
I'm interested to know how many different teams use your CI system, as well as how many different platforms (operating system, distro, programming language) you support.
Some companies have tons of old and new projects with very heterogeneous technologies in use. Imagine 50+ teams, several different programming languages, and things being deployed to different "hardware" (bare metal, cloud VMs, kubernetes, etc). It just seems like a lot of work to manage CI configs for all those different teams/cases, handle "support" requests from different teams, fix issues, and so forth. Hence, why the "easy way" out is to have each team manage CI configuration themselves as much as possible, to spread the maintenance cost across many capable developers.
Technically, version control lends itself naturally as part of the now well-accepted infrastructure-as-code mantra.
Operationally, version control is the one that developers interfacing most primarily, shifting the interactions to that interface would be benefitical to users.
Of course, DevOps as a skill set is becoming less and less relevant, given the increasingly integrated toolings that interfacing directly with developers, that's for sure.