I think a lot of this boils down to Procurement's good outcome generally being quite different than the good outcome for each team that wants a purchase.
To draw a parallel: imagine a large open source project with a large userbase. The users interact with the project and a bunch of them have ideas for how to make it better! So they each cut feature requests against the project. The maintainers look at them. Some of the feature requests they'll work on, some of them they'll take well-formed pull requests. But some they'll say "look, we get that this is helpful for you, but we don't think this aligns with the direction we want the project to go".
A good procurement team realizes that every time the business inks a purchase agreement with a vendor, the company's portfolio has become incrementally more costly. For massive deals, most of that cost is paid in dollars. For cheaper software, the sticker price is low but there's still the cost of having one more plate to juggle for renewals / negotiations / tracking / etc.
So they're incentivized to be polite but firm and push back on whether there's a way to get the outcome in another way.
(this isn't to suggest that all or even most procurement teams are good, but there is a kernel of sanity in the concept even though it's often painful for the person who wants to buy something)
To draw a parallel: imagine a large open source project with a large userbase. The users interact with the project and a bunch of them have ideas for how to make it better! So they each cut feature requests against the project. The maintainers look at them. Some of the feature requests they'll work on, some of them they'll take well-formed pull requests. But some they'll say "look, we get that this is helpful for you, but we don't think this aligns with the direction we want the project to go".
A good procurement team realizes that every time the business inks a purchase agreement with a vendor, the company's portfolio has become incrementally more costly. For massive deals, most of that cost is paid in dollars. For cheaper software, the sticker price is low but there's still the cost of having one more plate to juggle for renewals / negotiations / tracking / etc.
So they're incentivized to be polite but firm and push back on whether there's a way to get the outcome in another way.
(this isn't to suggest that all or even most procurement teams are good, but there is a kernel of sanity in the concept even though it's often painful for the person who wants to buy something)