200+ hours and 2 classes 90+ and not a SINGLE Citadel spotted

I understand they are random, but some of my friends are on the same situation as me. We cannot progress without them.

There is a quest named "The pinnacle of flame". You should go an investigate the burning monolith to make the citadels spawn of the atlas. Sometimes, if you haven't investigated the burning monolith, your citadel wont spawn no matter how far you travel on the atlas because the quest haven't been progressed yet.
The burning monolith is the weird looking red pyramid that is close to the start location of the atlas(home). After you have entered that and clicked on the door with the 3 fragments slot, the quest would say something in regards to finding citadels. After that the citadels would start appearing after you clear 1-2 new towers.

Hope it helps