I agree it's so rare to see a depiction of all the siblings suffering equally to survive, especially since Moryeon is the main instigator with trying to usurp the title. We got subtle hints here and there that the siblings are still mourning (Cheol and Moryeon looking devastated talking about it, Seobun investigating the reason) but I thought the siblings dynamic was being saved for season 2 after Moryeon and Yeju's love is established.
Well not to spoil anything but it seems that's the direction season 2 is heading, I hope it doesn't let us down after all the hints and speculation we picked up on

It's a weird recurring trope to kinda send a character's friends, job, family, etc. to the background in favor of the lover. With ML, his male relatives don't seem toxic (a rarity; please don't prove me wrong), and his brother was murdered...but it seems that the brothers and father don't have much of a relationship. It's kinda sad seeing MC and ML having so much fun at the festival and it's like "I love this, but I also wanna see ML bond with his family!" Plus I wanna know about MC's family--though it's a common trope to make them lonely so if they don't return to their world that they have no love lost.