The CPU implementation is done by Qualcomm, Apple, and the like. The CPU design is done by ARM, predominantly in the UK. The fact that Softbank (Japan) owns ARM has no bearing on where and who is doing the actual technical work.
https://en.wikipedia.org/wiki/Apple_A13
Yes it uses the arm instruction set, but it was completely designed by Apple. This is identical to Intel using the same 64 bit instruction set as AMD... you wouldn’t say AMD designs intels chips though.