"Riverdale" used to be compelling and thrilling. What happened?
Season One definitely had some problematic elements, but it was still generally good. It had a decent murder mystery plot-line, likable characters, and it was easy to follow because it focused on one thing; to find out who killed Jason Blossom. It was so good and it managed to satisfy it's target audience enough to hook them for another season.
However, as much you want to with Season One's ending, don't watch the later seasons. Everything just goes downhill from there. Season Two still had a decent murder mystery, but it also had so many subplots that made it hard to follow the storyline. Season Two also dealt with great inconsistencies in terms of plot twists and continuity. Plus, you begin to lose respect for the characters as their arcs get thrown out the window with each idiotic action. After all, who THE HELL thought it was a good idea to show a 16-year-old CHILD stripping in front of her boyfriend, adults, and mother!? By the end of Season Two, you're struggling to ponder what is happening.
By Season Three, everything went to hell. The plot became inconsistent and confusing and the characters just became annoying, frustrating, and unrealistic. You thought the 16-year-old stripper was bad? Well guess what? Now you have to deal with a bunch of children retaliating against their parents by running an UNDERGROUND BAR!? Don't even get me started on what the show was about anymore because I couldn't focus on anything what with the one million subplots.
In conclusion, if you're interested in watching Riverdale, do yourself a favor and watch Season One only. That was the only season that writers put thought and care into. You'd be wasting your time with later seasons.