I binged S1-3 and its been a long while since I have binged any show whatsoever.
Smiling Friends feels like the anti-Rick and Morty, in the sense that its a show that isnt using its mature rating as an excuse to finally be intensely and needlessly edgy and to say swear words (tho never slurs, ever), while standing on your soap box and drop some redditism. S.F is a show that feels like a "mature" cartoon on the veins of Chowder, Gumball and Flapjack, shows with surrealist style that often has mixed medias thrown in to add to the crazy feeling, added also some spirit from flash animations.
Another thing that helps S.F over a good chunk modern adult cartoons is the fact it has a comparatively unique setup while also NOT using the mature rating to having absolutely unlikable characters. Dont get me wrong, a lot of characters can be rather unpleasant and our four leads are no angels but their worst moments feel more human than contrived, and it never goes overboard with it. And I cant believe Im going to say this but it is refreshing having a character like Pim among the adult cartoon scene, a character that acts like a lite classic spongebob and wants to be positive and spread positivity and you'd think that Charlie would be the Patrick or Squidward of the duo but he is also funny and enjoyable and he even when he isnt the most pleasant, he makes it clear he legit likes Pim and will stand by and for him when push comes to shove.
And its just an overall very funny show, I dare say its an example of "good" millennial writing, in the sense that it clearly shows that the ones behind it watched the classics, both TV and online, and arent afraid of dropping references for those "in the know" to get it but not too much in your face where its distracting to those that dont get it, an example being Chill's cameo, its quick, he does his "Number 15" bit and the plot moves on. The plot doesnt stop and makes it overstay its welcome, its there and boom, over.
That isnt to say that every episode works for me and even the ones that dont, still work for me. There is no "bad" S.F episode for me, just weaker ones. If I had to pick, I'd probably go with Mole Man and Silly Samuel (oddly enough, both S3 episodes) as the former is almost entirely composed of dick jokes, not even funny ones since they dont even bring up the obvious solution for him to wear pants or something (or even make a joke out of it), nvm that the Glep and Alan section just are a torture section for the two of them until the A Plot suddenly decides to crossover. As for the latter, the Silly Samuel sections are just mediocre, not bad but just meh, with the Alan and Mr Boss B plot being the "saving grace" as its actually legit funny (alongside with the Bob Chandler reference that was all over social media for a couple of weeks). Besides those two, I legit enjoyed all episodes, with them all maintaining a good balance between being episodic but also keeping a lite continuity (its almost impossible to not have it in the days of streaming).
Overall, its one of the best shows in modern adult cartoon history, which maybe isnt saying much given the competition but if it got someone like me to get off my ass and actually binge watch anything? That has to mean something.
Edit: iirc, someone properly explained that S.F surprisingly only lets bad things happen to those that deserve it, at least most of the times and it doesnt take some sick enjoyment out of hurting innocents just because "oh hey, we are an adult cartoon so we can get away with senseless violence!". An example is the princess from the enchanted forest episode, if this was, say, Rick and Morty/Family Guy and etc, she would have been killed by the explosion and our duo (covered in her blood) would be all confused and scared and talking over themselves because haha shock value or something. But in S.F, she is able to throw the bomb away in time and is able to finally smile. Its small but its def. the sort of thing that you notice in the back of your head and you appreciate it.