Thunderbolt is dead , and it dies the moment it came out.
Apple exclusive technology when it first came out: check
Not industry standard: check
Extremely expensive both in terms of 3rd part accesories and including it in computer: check
In fact the port on "thunderbolt" couldn't even be agreed with. Apple had the display port style port, I think Sony released it as a USB style port.
Its just a big expensive bag if hurt.
Usb3-c is clearly the future. The port is small enough to have on mobiles and tablets and full sized laptops and computers. Its data transfer is up their with the first gen thunderbolt , it can connect with all sorts of things etc.
Essentially its what thunderbolt was meant to be but wasn't cheap enough or industry standard.