They have never been traditional idols and have always behaved freely, which has allowed them to achieve artist status and recognition among the general public. The same thing happened to Mamamoo, and to another extent to IU as well. It's a status that they owe to their talent and their way of being themselves, not to anything else.
For the 4th generation I do not see any group reaching this status for the moment. However, I can clearly see a person becoming one very soon, who is Soyeon. She follows exactly the same path.
Oooh yes, i have mad respect for Soyeon. She's an artist for sure.