USB-C is only a connector/socket - a device having a USB-C socket does not guarantee much beyond being able to plug a USB-C connector into it.

Some USB-C devices only use the port for charging for example. Others might only support USB 2.0.

Getting a display out from something with USB-C socket needs the device to support something called DP Alt Mode.

Note that cables matter too - you can have a DP alt mode enabled monitor and phone, but if you have the wrong cable it won’t work. Welcome to the future.