Because of apple’s size. And because we just witnessed a death of a proprietary connector. A major win for the consumer and for the universtal serial bus projects overall mission.

On a side note. Apple has been part of the usb c project from the beginning and based on some biographies - they worked hard to never release Lightning. But they needed to drop the old 30pin connector and found usb C not ready when they needed it - so they release the lightning port instead. Then stuck to it for obvious profit /ecosystem reasons.