People don't consider IU fan driven though. Her achievements are not ridiculed like others are.
I think the point of this thread is if acts consistently get some amount of uls than they are fans. It's not just first hours that count. SOME songs of acts are heard outside of their regular fans and thus perform better than their songs perform on a regular basis.
For Twice I think they lost part of the fanbase that streams more and were fickle. And I think their album sales are not growing, but are more stable.
Almost every song/album that IU releases achieves viral-level stats tho in terms of digital sales. So either her fandom is so big that they're able to give her SOTY-level sales with every release, or she also has GP support in addition to large digital listener base.
Going off what was said earlier in the conversation that all national-level hit songs need some kind of non-fan support in addition to fans - so either IU fanbase is that big, or her songs get a lot of non-fan support, or IU is just an anomaly and doesn't rly fit well into this narrative.