The Apple MacBook Pro Early 2015 Retina has an 802.11n WiFi standard which is better than most laptops of a similar spec and age to it. Most MacBooks that were launched around the same time as it have an 802.11a WiFi standard. In addition, this portable PC have 802.11ac and 802.11b and 802.11g WiFi standards.
This notebook PC's Wi-Fi standard (802.11n) is in fact the best Wi-Fi standard amongst all MacBooks that have been available for a similar time to the MacBook Pro Early 2015 Retina.
The worst Wi-Fi standard across comparable types of notebook PC is 802.11a.