“Do Jughead and Betty even have anything in common?”You mean, aside from the sleuthing?
Literally the reason they got closer and fell in love in the first place was because they were both writing for the Blue and Gold. They’re both writers, that’s what they have in common. Jughead mentions Betty reading his manuscript and critiquing it, so supposedly they do spend some time offscreen bonding over their passion for writing. You don’t have to ship them to notice that stuff. I don’t ship Archie and Veronica but that doesn’t mean I didn’t notice that the show purposely made them both singers.
It’s painfully clear to me that this show gave a lot of thought into establishing its ships. While it’s important to show couples supporting each other through difficult times (As Betty/Jughead and Archie/Veronica have both done), the show also establishes that these pairings also share common interests, to make it more believable that they would click well together. For Bughead, it’s writing (Jughead seems to lean toward non-fiction, and Betty journalism). For Archieronnie, it’s music/performance arts (with a dash of songwriting on Archie’s part and dancing on Veronica’s part).
Do I think the show could have done a better job showing this more clearly? Absolutely. But does that mean it’s not there? No.