It can be faster when using a specially-built adapter like that, but not with standard Lightning cables as they don’t have enough wires. Apple would have had to

It can be faster when using a specially-built adapter like that, but not with standard Lightning cables as they don’t have enough wires. Apple would have had to create a “fast data Lightning cable” standard and have different tiers of cables. That would be a messy enough solution that they might as well have just switched to USB-C instead. Which they have done.