And look how much thinner. A large part of that is the need for physical ports which although they may loom small on the outside, also take up space inside for the boards that convert signals. Now those conversions happen in the dongles if needed.

The real problem is that USB didn't implement a hub standard so most hubs have had to use old hub standards and just have a single USB-C connector and the rest USB-A, hdmi, etc. There haven't been many purely USB-C to USB-C hubs to allow for connecting lots of USB-C devices to a single port and usually they end up losing features or splitting bandwidth instead of sharing the full bandwidth.