Unfortunately, it seems it cannot be used just as a keyboard for other devices.
I have a similar gripe with iMacs and most all-in-one PCs that they cannot be used as a monitor for other devices. Once the PC/Mac inside becomes obsolete, the whole device becomes useless even though it has an excellent display that still works.
Are you sure about that? Other pis can use gadget mode to act as a device (like a keyboard). Has that been specifically disabled somehow for the pi500?
That's not what I meant. I meant just using the keyboard part as a keyboard, out of the box, without the need to tinker with the pi's software and/or hardware.
I have a similar gripe with iMacs and most all-in-one PCs that they cannot be used as a monitor for other devices. Once the PC/Mac inside becomes obsolete, the whole device becomes useless even though it has an excellent display that still works.
This is kind of the keyboard equivalent of this.