Macs have had Thunderbolt (which is just another peer to peer protocol much like ADB & Firewire rather than master/slave) well prior to USB-C. The dedicated USB-C to USB-C link is a superset of USB but not quite Thunderbolt. ADB was on the first Mac, so Mac's have done Peer-2-Peer natively forever.
If I made a mistake in assuming it was that Saitch didn't have 2 Macs. I'd wager I didn't make a mistake because Apple make it so easy, and so well publicised that it's not something you'd miss if you had an old Mac and just bought a new Mac.
Happy to be corrected however if Saitch does happen to have 2 Macs.

