i'm going to review each individual season.
season one: absolutely brilliant. may have had its downs but was by far the best season out of all. at this point you have no idea who the murderer is and when it is revealed, the story all fits together. great story. great writing. awesome season. absolutely loved it.
season two: really good, may have had its plotholes and funny moments but still good.
season three: makes hardly any sense at all
season four: pretty much on crack. no storyline. every character they try to make seem normal is actually, in need to be placed in a mental institution. toni's pretty much the closest to normal you'll get.
in conclusion, riverdale lost its quality after season one. every episode of season one had me (and so many other viewers) hyped for the next one and i was counting the days until the next episode came. now i'm absolutely dreading season five. how are they gonna butcher the characters now?