I'd say its less common for a project to have budget for a technical writer. I think there are plenty of people who have stellar writing ability, it's just nobody is willing to pay for it.
I remember back when I ran Ironport appliances it came with a giant manual - maybe 1000 pages. It was very well written, had CLI excerpts, explained theory, etc. It was amazing.
Companies see things like admins, technical writers, configuration management as excess. Technology today has reduced the need for these specialist-but-not-core-to-the-business roles. So the work is increasingly piled on the specialist in other fields rather than being a specialist position of its own.
"I'm not paid to write manuals" is a common refrain in places I've been. The developer wants to write the code, maybe write the spec and design document. But they have no interest in writing the manual because "it's not my job." Only, today, it is their job because their employers (contrary to last century) don't employ writers on staff and contracting for fast changing documentation to keep up with fast changing systems isn't worth the effort. So it's up to the dev.
Same with many other tasks. There have been some really good articles about the impact on professions like professors, teachers, doctors and others as their workload has increased. Why? Because technology has reduced each individual task to something small, but cumulatively it's drowning them (and us). Something has to give. The shifted work makes sense until you look at the aggregate impact.
In the case of doctors, they have little they can avoid doing so they just drown in work. Teachers are made to work 12-16 hour days during the school year. But we, the programmers, get to skimp on these things (and hurt our users) because it hasn't yet hurt our bottom-line or cost any lives (safety critical systems still do a better job here out of necessity).
I remember back when I ran Ironport appliances it came with a giant manual - maybe 1000 pages. It was very well written, had CLI excerpts, explained theory, etc. It was amazing.