Aespa didn't really flop, so that aside...
YG's groups have always done well from the get go. Always. Big Bang sold 150K albums and reached #3, a crazy strong debut in freaking 2006, before kpop had a strong international following. 2NE1's Fire almost won a music show trophy right off the bat (basically unheard of in 2009). Winner's Empty and iKon's My Type both hit #1 on the charts and had more than 1.5 million DLs. Blackpink's double debut songs both did incredibly well internationally (Boombayah hitting #1 on Billboard and Whistle hitting #1 in Korea). AkMu's 200% topped all the Korean charts.
The weakest debut of all of them is Big Bang whose We Belong Together "only" got to #5 on the charts.
So the fact that Treasure came from a company with that strong a track history and their debut song couldn't even break the top 100 on Korean charts was hugely surprising.