The two metre cable supports Thunderbolt 3 data transfer up to “40Gb/s, USB 3.1 Gen 2 data transfer up to 10Gb/s, DisplayPort video output (HBR3) and charging up to 100W”, according to Apple. This means it’s very capable and need only be used by those with specific high end needs.
But it doesn’t stop the price being an awful lot for a cable for regular folks. For design and video professionals, a 2m cable capable of those speeds is likely a reasonably sensible purchase if it can link their machines to hard drives or displays.
So, yes, this is another expensive Apple accessory. But it’s not as ridiculous as those £700 Mac Pro wheels.