My thoughts are that they did this to force less savvy individuals deeper into the ecosystem.

Joe Consumer will buy an iPhone, AirPods, and Mac Pro without thinking, and iCloud will manage the syncing, and the nightly charge most users require will happen overnight next to their bed. They'll never miss the iphone->mac cable because they'll never need it. Same with the headphone jack.

I really miss the 3.5" port, but I get why Apple did it. It's consumer unfriendly, but good for business.