>>37904827SM has three mature episodes that Pokemon hasn't really seen before.
>Litten/Stoutland>Sophocles/Poipole/Minior>Mallow/ShayminThree episodes don't make the entire series good, just like six months of XYZ don't redeem XY for its two years of filler crap.
What SM has: the best background artwork ever, generally high-quality hand animation, a well-developed region that feels inhabited by people instead of NPCs
What it doesn't have is great character artwork or exciting hooks to engage the viewer. It's boring in the sense that you don't want to watch it, but when you watch it you aren't frustrated enough to turn it off.