A good manager deals with the paperwork of requisitions, financing, and getting "buy in" from "customer" departments and management.
A good manager makes sure your projects have visibility, and that their successes and ROI are broadcast through the company so your department doesn't end up downsized.
Having technical knowledge is good for a manager to understand what their team is doing and what they're saying in meetings, but "technical knowledge" is not and never has been what the manager's job is about. A good manager doesn't need to understand the details, because they're not micro-managing their staff.
So how is this non-technical manager supposed to provide oversight, manage conflict, improve workflows, and improve processes when they don't understand the technology or tools?
Seriously, when the shit hits the fan non-technical managers are just guessing at how to fix it and why it happened in the first place? I'm sure we have all worked with plenty of bullshitters that make the rest of our lives hell. And they get to exist and continue to exist because of non-technical managers that can't filter them out.
I know it is tough to keep up with technology when being a manager because of all the things you mentioned. But there is a reason why we are paid more to manager engineers instead of Wendy's workers. We are expected to know more and actually lead by example; not just be a baby kissing politician.