I think you greatly underestimate how much of this "natural convergence" happened because of EU influence. See the memorandum of understanding of 2009.
An MoU is not legislation, it's agreement to work together on a common goal. It can be helpful but isn't binding. From the MoU:
"The Signatories retain the right to withdraw from this MoU at any time with immediate effect."
I was demonstrating convergence on USB-C across digital devices. An MoU from 2009 of phone manufacturers agreeing to use microUSB can only partially explain that. Maybe it helped give the idea of USB charging additional momentum. Maybe it would have happened anyway as microUSB was only itself introduced in 2007, and the phone landscape was transitioning to smart phones at this time.
"The Signatories retain the right to withdraw from this MoU at any time with immediate effect."
I was demonstrating convergence on USB-C across digital devices. An MoU from 2009 of phone manufacturers agreeing to use microUSB can only partially explain that. Maybe it helped give the idea of USB charging additional momentum. Maybe it would have happened anyway as microUSB was only itself introduced in 2007, and the phone landscape was transitioning to smart phones at this time.