*may destroy motherboard
Consider how much a 10 GbE card still costs -- this is the same speed! Apparently, it's not cheap making chips working with 10-20-40 gigabit/s line speeds but the market demands low cost. USB C wouldn't get far if a plain USB C to DP adapter would cost a hundred bucks.
You can thank the laws of physics for that because at 10+ gbit data rates you start needing crazy internal clock speeds (which can be significantly higher than the input clocks). Since the distance a signal can travel before it loses too much energy to register logic HIGH is proportional to the wavelength, you have to pack everything close enough while still doing what your specs call for. In the case of 10GigE and USB Type C, this means having to move to smaller fabrication processes than most companies are prepared for or even have access to.
Most protocols designed to be that fast are either massively parallelized to avoid this problem like PCIe/DDR2+ or very expensive to implement as peripherals/silicon like MIPI3/10GigE/USB Type C.
The only strange thing here is how five years ago we already had USB 3.0 and DP 1.2 devices in abundance but ten gig is still somewhat problematic.
That is why we need competitions. Sadly patents also prevent competitions from happening.
Another example: you can buy a small and cheap USB C to DisplayPort adapter with power passthrough (< 20 USD). You can buy a (relatively) small and cheap USB C to dual DisplayPort MST hub (<50 USD). You can not buy a USB C to dual DisplayPort MST hub with power passthrough unless it's a full dock, huge in size and expensive (200 USD at least).