WiFi In The Sky: Which Airlines Offer Passengers Free Internet Access?

In recent years, the availability of WiFi onboard commercial airlines has been growing. Now, with services like Starlink rolling out, in-flight WiFi is exploding, and an ever-expanding list of airlines is offering in-air connectivity. However, only a few airlines offer onboard WiFi for free (and airlines offer it for free, but to certain loyalty members or passengers with higher-class tickets).