A common complaint or concern I hear with Task Manager is that what it reports doesn't seem very useful or that they wish what it'd report was something more meaningful. A commonly cited one is CPU % Utilization, which people have commented that it doesn't really represent what the CPU is actually doing.
After stewing on this I thought of a way to think about what Task Manager is better thought of: a status report to a company's department head. For example, let's take a company's head of the software development department. They're more interested in the progress of each project or program, if people are doing things or not, how much money is it spending, etc. If we were to take a real life example, say you're the software department head for Apple. You'd care about things like how iOS, iPadOS, and macOS are doing, what their staff allocation is and how busy they are (because this may mean you need more or less people), and how much money each of those projects are spending. What you wouldn't care about are things like what each individual person is working on or what minor hiccups there are in the development process. A department head wouldn't care about the little things, they care about the big picture.
In the same vein, Task Manager should be used to look at every process and see what's taking up your hardware resources. Hardware resources that execute something like the CPU and GPU should only indicate how busy they are. Resources that store something like RAM and storage, should only indicate how much stuff they can hold (though storage is a strange one since it also has a queue, so it's more useful to show how busy that is over how full it is). Everything has their little details, but it's still important to remember: Task Manager is for, as its name implies, managing tasks. Knowing the intricate details of say how the CPU is being used isn't useful in this regard. It's only useful for someone who's developing software and wanting to know how they can optimize. Likewise in a company, there's probably someone who looks at how people are developing software and it's their job to make sure things run smoothly