At my job, a decade ago our developers understood how things worked, what was running on each server, where to look if there were problems, etc. Now the developers just put magic incantations given to them by the "DevOps team" into their config files. Most of them don't understand where the code is running, or even what much of it is doing. They're unable or unwilling to investigate problems on their own, even if they were the cause of the issue. Even getting them to find the error message in the logs can be like pulling teeth. They rely on this support team to do the investigation for them, but continually swiveling back-and-forth is never going to be as efficient as when the developer could do it all themselves. Not to mention it requires maintaining said support team, all those additional salaries, etc.

(I'm part of said support team, but I really wish we didn't exist. We started to take over Ops responsibilities from a different team, but we ended up taking on Dev ones too and we never should've done that.)