A developer (or even administrator of a single computer system) is not the user of something like this, typically.
Here's an example:
A small manufacturing business may have a dozen different machines. Each one has a set of software to control it, running on a computer embedded in the machine. The business also has a website (developed by a contractor), a bunch of software packages purchased from different vendors for accounting, inventory, payroll and scheduling. They probably have some internal home-grown tools too.
1. A new remotely exploitable CVE is announced in a widely-used open source library. Is the company vulnerable to it? Anywhere?
If each one of the pieces of software was delivered with a SBOM along with the actual code, you can use tools like this to look at this globally. It starts to make more sense at the scale of "all the software in the business" is provided by tens to hundreds of different vendors or teams that not only don't communicate with each other but also don't even know that the others exist.
My client isn't exactly a "small manufacturing business", but they do subscribe to such a service, and they did have the Java issue in a parent process. They have a security guy who's the main one expected to look at these, but he's not the one operating anything directly, so he can't be expected to know every last random lib that's used.
So when the Log4j2 issue came up, for example, he was aware there was "a Java issue" but had no automated way of knowing which systems, if any, were affected.
There's a cottage industry forming to do this sort of thing, mostly in the medical field, but it'll probably spread out.