Personally I think that we should trust the Staff and AirVPN.
We trust this service to protect our privacy, and AirVPN's mission statement (https://airvpn.org/mission/) is crystal clear.
I don't think they are a bunch of lazy masochists who like scourging themselves with hundred of thousands lines of code instead of few thousands, they are people interested in standing by what they have written and when they say that they prefer using technologies validated, audited and tested they are just doing what we pay them for: protect OUR privacy and freedom; moreover, the service is not just used by Netflix users, torrenting people, and so on, but also by activists, NGOs, journalists and dissidents who can seriously risk their life if their privacy is left "unprotected" because the software they are using has not been properly and thoroughly tested.
At the moment, to my knowledge, AirVPN is using the state of art (technically a bit more because they have improved OpenVPN forking it) of the VPN technologies to protect users' privacy both on desktop and mobile.
When, and if, the time will come, and Wireguard will be the de facto industry standard (because audited, tested, validated in different case scenarios over the months/years) and will replace OpenVPN because it has 1) better performances 2) stronger user's privacy protection and it will be 3) easier to maintain I'm more than sure that it will be adopted also by AirVPN.