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".

Samsung DeX is pretty good but I think they're phasing it out.

I've used it while on holidays connected via HDMI to the TV in the hotel, with a bluetooth keyboard/mouse and it performed admirably.

Can do the same with iPhone. Sending this from an iPhone 15 connected to the same dock + Logitech keyboard / mouse used for my MacBook.

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

That message appears when the microprocessor in the cable crashes or hangs.