This might shed some light as to why: https://www.youtube.com/watch?v=-BLgS7m0W94
tl;dr: phone webcams have DMA, laptop webcams are using USB.
tl;dr: phone webcams have DMA, laptop webcams are using USB.
I'd say a more likely (and harder to fix) explanation is that the phone ones can be deeper; laptop ones have to be very slim to fit.