Well, the most obvious answer is that the administrators are the ones that hire the adjuncts, if you follow.
All uni’s I know of in the U.K. have hired hordes of admin staff. I think this is largely due to centralisation, eg rather than have an exam admin in each department, you have a team in a central building. This sounds like it will be more efficient, deduplicate effort etc, and also has the added imagined benefit of presenting all the courses in a similar way, so you can have a “uniform” and “unified” student experience.
But this is a fantasy.
The reality is that different departments and different courses need to be run according to their specific needs. So the central administration then either fails to address this or hires more people to compensate. And once you remove people from their actual job (ie take them out of the department and change the job from “helping lecturer X get this exam done” to “execute processes A B C” then the potential for bloat and empire building skyrockets. You end up with all sorts of strange initiatives, buildings, and job positions, that seem far removed from simply administering teaching and research.
At the same time the U.K. gov slashed funding, moved to a reliance on tuition fees, and pushed universities to run like businesses. Their ostensible purpose and the incentives they face are now dramatically misaligned, so it’s no surprise that the outcomes we see make no apparent sense. It’s far more important to bring in grant funding than provide good education, for example, when you know students will keep paying regardless.
