Like I said, it can work, but relying on "word of mouth technicians" isn't very practical. There are also times when, after an update, things just break, and the "technician" may not even be able to fix the issue in a timely fashion, especially issues related to sound or QE/CI. I've done enough digging around and tinkering with kext files and video drivers to know that it can sometimes take days of concerted effort to fix these issues. I'm sure mileage varies depending on one's needs or the particular hardware configuration but you're rolling the dice every time you update.
Definitely, they've all become paranoid about updates or installing anything which is not absolutely necessary. They are a version or two of macOS behind, and never update without confirming with the technician.
I shudder at the security implications, but I'm told it has become quite common after the trashcan came out.