I have one 2019 MacBook and a 2021 MacBook Pro connected to each other via the Thunderbolt ports to do a migration. Given there are only about 700 files to transfer, I would expect it to take less than 2 hours tops.

Instead it is transferring at only 21 MB/s, which is dramatically slower than a WiFi download. Current estimate to complete is 49 hours.

What is going on with my connection? Is there anyway to speed this up?