I also prefer docks to hubs, for the same reasons you mentioned. There are still some pretty big gaps which need to be addressed before we can use a single cable for everything.

First, Mac OS still doesn't support DisplayPort MST. If you have two or more non-Thunderbolt monitors, you'll need to use more than one port.

Second, many companies require their employees to use tokens such as Yubikeys, which are USB devices plugged into a laptop operating on human touch. Even if you dock your laptop, you will need to keep it within arm's reach so you can touch the Yubikey. You could remove the Yubikey from the laptop and plug it into your dock, but that defeats the purpose of docking.

Ultimately, I just want more desk space, and I consider both the dock and the laptop to be clutter.