It is not for preventing you from taking screenshots, if you insist, you can do it with another camera. It is to prevent malware and "helpful" AI tools from doing it for you and then uploading the picture to who knows where. Signal does this too, though I think it is optional.

Beyond preventing screenshots, it blacks out the window content in the task switcher, which is useful if someone is looking over your shoulder. This, by the way, is a good way to check if screenshots are allowed. If the window appears black in the task switcher, screenshots won't work.

The idea is similar to the "**" password fields.

It's really stupid idea, that results in photos of sensitive information displayed on my device on other devices that I don't control and sensitive information wrote on paper in random places.

Password fields are inputs. Screens are bi-directional.

I mean if the goal is to prevent potential malicious apps from taking screenshots automatically; instead of saving a clueless user from themselves or worse getting in the way of legitimate users I believe that the proper solution is to disallow programmatic screenshots while still allowing screenshots when there is the correct button press (and ensure that this cannot be emulated). Windows reserves ctrl-alt-delete as a direct signal to the kernel for security purposes. Why can't android do the same?