You can do that with iPhone, too, using the (poorly named) "USB Camera Adapter", which splits out a USB type-A jack. (I assume you need a similar adapter on most Android phones, too, since I've never seen one with a type-A jack built in.)

I can plug in the same USB-C dock I use for my Mac and everything just works on the android phone.

You even see the phone screen mirrored on the monitor, complete with mouse cursor etc.

The sad thing is it is just literal copy of the phone screen. It does not have a "desktop mode".

I don't think so. I think usb-c based phones don't need any type of active adapter.

For example, on usb-c iphones, I can plug my camera with a c-to-c cable in mass storage mode and it shows up. So I expect a dumb a-to-c adapter would work. On my lightning-based iphone, a c-to-lightning cable doesn't work.

I'd assume it's the same for androids and keyboards.

reminds me the time i had an iPhone SE (1° gen) and i could play 1-3 minutes of garageband with my Korg keyboard using it and then it stopped saying my (adapter) wasn't offcial :) the official gadget in Brazil was > 10 times more expensive than the cheap copies