I loved Sliders when I was a kid, and I have chanced across multiple DVD box sets of it over the past year or so, so I have seen Seasons 1-3 very recently and they're great. I can tell you that yes, the writing team behind Sliders could think of many other plot lines than that one. They have interesting hot takes on political issues that we see even in the present day, such as an episode where women have all the positions of power and men are seen as "the weaker sex" (S01E7). They have several episodes with actual alien invasions, and according to my reading, these episodes become more frequent later on, beyond the point I have seen up to. They have a time travel episode (S03E4). They have multiple episodes featuring DINOSAURS, but those are not as good so shhhh. It sounds like at some point, they have a racism episode (S04E11), although it's a late episode that I haven't seen so it might be terrible too. And even before the sliding device magically allows them to travel to places outside of San Francisco, so back when they are permanently in San Francisco, all of those episodes were filmed in Vancouver.
I honestly disagree with you so strongly on this that my next question is: is there another thing called Sliders that you're talking about, and I've just stormed in here with a load of totally futile trivia about a forgotten TV series when you were really asking about something else?