Your not alone dude. Still my favourite comfy sol type show of all time.
Nice artstyle is certainly part of it.
Believable but still kinda over the top cute characters.
Super cute interaction between the characters. Some shows to me just feel kinda too forced in this or just off.
Great voice acting. Alongside nice songs
Satisfying length of the show, doesn't drag on for sure and doesn't feel too short (beyond always wanting more of a good show).
I think its just got the best balance of realistic to super moe cute of any show around. makes the characters and story more satisfying to me.