You can have authority while still having someone be accountable to the org. We had a situation where we were paying for three different presentation tools and two whiteboarding tools for a team of 30 people because two people had minor preferences.

I have to request a limited card for recurring spends, which comes with a "why" box. It makes people think about what they're buying just a tiny bit more. But I've never had a single purchase denied (other than the time I accidentally paid for a personal holiday on my work card because Google pay's default payment card on device and online are linked)

Generally, nobody has authority. Even the highest executive has to fight procurement in a big corp. Own a VC-backed startup, the investors want you to get prior agreement on 'large' purchases. Maybe if you are the sole owner of a small firm without a purchasing department.

Politics always has people insert themselves in the flow of money.

If you get what you ask for without fuss, then it's not an issue. It becomes an issue if you have to slog your way through corporate bureaucracy^H^Hzy to get basic things.

It depends on how strictly the request is scrutinized. I can spend exactly 0€ myself. But when I request a new machine, the order is placed immediately.

On the other hand I requested three months access to frontend masters which was promptly denied citing I should use our Udemy subscription.