They're not software engineers or data scientists if that's what you mean by "highly qualified".

Datacenters techs do the physical parts of the job we once called "system administrator". That definitely requires skill and attention to detail, not just the ability to "install some parts".

When the tech industry transitioned from on site systems to datacenters and big compute / big data, "system administrator" got split into "site reliability engineer" and "datacenter technician" as they scaled independently, with datacenter tech being focused on manufacturing and physical troubleshooting.

They have always been the "blue collar" workers of tech, both in terms of pay and prestige. Like tech support, the job is considered more of a stepping stone into the operations (not R&D) side of big data companies.

That all said, the qualifications of applicants for a job depend a lot on the labor market, in particular, the desperation of applicants. During the dotcom bust, a lot of CS grads (including me) were applying for technician jobs.