Ephram/Amy are a prime example of showing them "together" without the romantic tag always being in place throughout the series. During the time periods they weren't officially together romantically, you still felt like they were together because of that emotional connection. Even if season 2, Berlanti separated them a bit, he still had them together during very important moments while they were with Madison and Tommy. You still felt that E/A and their dynamic was 100% way more important than their temporary romantic relationships. They were together even when apart. I wish Mark would have done something like this with Leyton instead of giving them amnesia in season 2.

Riverdale, I am so pleasantly surprised. Before the series got started, I assumed the dreaded triangle would dictate. Thankfully, the showrunner was clever and put the female friendship between Betty and Veronica as a cornerstone of the show which naturally breaks down that triangle. It's pretty much established Betty/Jug, Archie/Ronnie are THE two ships of the series and I wouldn't be shocked if we never see Betty/Archie romantically which is fine by me. Plus, like you said, the mystery/crime is a huge part of the series which absolutely helps keep the characters connected, and greatly prevents that teen romantic/triangle soap opera drama from showing up that much as well. It is so refreshing.