Too early to call LSG or HYLT a national hit. HYLT had the right peak to be called one but it still needs to rack up some more digital Gaon points. LSG has a big strike against it since it never hit #1 anywhere, but it's longevity is breathtaking. If it breaks the current record of 22 weeks in Melon's Top 10 held by BB's Lies (I know Dynamite has broken it but i dont consider it a "national hit" eligible song), it's going to be really hard to argue against LSG.
And someone said above that national hits need to be era defining or whatever, and to me that's crazy lol. There are literally tens of thousands of songs released in Korea each year. Probably hundreds of thousands. If a song makes it in the top 10-20 songs of the year, that song has already reached the top .001 percentile of Korean songs. Yeah, it's a national hit lol.