Those are all useful things though - they're not useless, they're just not working at full capacity.

Systems administrators do have meaningful metrics though...

I'm assuming you mean glorified IT so I'll start there. Hardware breaks down obviously, but do does software. They have update schedules, so every few months they have to test updates, research it, and decide how when to roll it out. They have to periodically check equipment, and convince the company on what to buy when. And obviously, at any time something can explode and stop the entire company from working

For systems engineers for more complex systems, you have the same things, except the stakes are much higher. So there's a lot more math, test systems, and so on.

The metrics come from methodology, not just nothing going wrong.

When I think of a truly useless job, I always think about sales. What do they actually do? The better they are is basically how much they can force others to act suboptimally - to pay more, to buy more, to trust a product more because it came from someone charismatic.

I mean sure, they could be using their powers for good and actually helping connect buyers to appropriate products, but most of that is because marketing has muddied the waters. And sure, they might actually be handling necessary logistics with expertise others don't have, but I'd go so far as to say most of them do more selling and less facilitating

It just seems like a lot of humans being stupid humans. It's work we entirely created for ourselves. And sure, it makes money for a company... But even that's just playing with made up numbers.

Which brings up a whole lot of even more roles based on stupid humans being stupid.

(And reception is again logistics and support - could you imagine walking into a doctor's office and just waiting in an exam room until someone shows up? Their presence enables someone with presumably valuable skills to multiply their productivity)