Ethernet adapters conversion from MacBook Air (Mid 2012, 13") to MacBook Pro (Late 2019, 16")
The Belkin USB-C to gigabit adapter that Apple sells online is the best bet for you.

Belkin USB-C to Gigabit Ethernet Adapter

Much better than chaining Apple gear in performance, reliability, price and power usage. The Apple thunderbolt 2 model works fine with the Apple adapter - just you have overkill and two joints to manage.