I havent seen many desktop like workflows on it with several "big" apps open (and running cpu) at the same time, most ive seen was one software at a time or games. Cooperating with yourself is relatively easier, no ?
The reason you don't see lots of "big" apps at once is because memory! RAM was expensive.
If you run a CPU-bound task on AmigaOS, you can use ChangeTaskPri on it, and you can easily see the difference. At its default priority of 0, the mouse pointer is still smooth but other applications start to clam up and starting new things is slow. Reduce the priority to -1 and everything's full speed again. Raise the priority to 5 and you'll have trouble moving the mouse pointer. Raise the priority to 20 and the system hangs...
I don't think you've truly experienced "cooperative" multitasking. Try RISC OS, which literally passes control around between applications and has to wait for them to give it back, unlike AmigaOS which will take it back from them. Any kind of error is an immediate modal window that stops the world. Accessing a disk stops the world. Pressing F12 on the desktop drops to a command prompt and stops the world. You can open a command prompt in a window but it runs at a fraction of the speed of the global command prompt.
Shared libraries were typically loaded only once into the system's single shared address space. Any process could potentially overwrite another task's memory or shared library state.
I don't have my old setup ready but if I boot into Pimiga, I get about 60 task and processes running.
If you literally mean "seeing" workflows, because of the small monitors back then, you usually didn't have open programs side by side. The Amiga allowed to have multiple screens that were basically a better version of virtual screens combined with fullscreen mode.
Here is an example of somebody having Deluxe Paint open and the Workbench.
https://retrocomputing.stackexchange.com/questions/24842/ami...
The pinnacle of workflow design on the Amiga was of course ARexx which allowed applications to communicate through message ports and automation scripts.