First off, their design! Both Stufful and Bewear are so cute, especially Stufful! I especially love their ears. They look like a mother's headband or bonnet! You just want so much to hug them but then you get to the lore that Stufful hates to be touched and will punch the daylights out of any stranger that so much as lay a finger on it and Bewear love to hug but they're so unaware of their own strength, some have accidentally killed their trainers (or at least left them with serious injuries). In short, you have teddy bears that can beat you up if you mishandle them. And we all know how popular the Pokemon with dark PokeDex entries are.
Then there's the games! I've caught Stufful in both Moon and Ultra Moon (named Fluffy and Kiteruguma respectively) and I can definitely say they are worthwhile Pokemon to use! They are also absolutely adorable in Pokemon Refresh and have possibly the cutest cry in the entire games.
Both Fluffy and Kiteruguma evolved into powerful Bewear and while their ingame cry isn't as cute as it's pre-evolution's, their strength makes up for it and if you're still disappointed by it's ingame cry, the anime has provided a much cuter yet intimidating (to your eardrums) voice for it.
But what really made Bewear become my favorite Pokemon from Alola is the anime. In the third episode of the series, a wild Bewear decides to take the Team Rocket trio into her den to feed them delicious honey she's made and from that point on pretty much adopts them as her children. This Bewear does everything in her power to take care of them, feeding them the best fruits, berries, and honey she can provide for them, keeping the den a clean, comfortable, and safe place for them to live, defying physics to save them
, letting them build a base within the trunk of the tree, snuggling with them in the grass, comforting them when they're sad or scared, taking in all the weird friends they pick up (from Mareanie to a random secretary they're with), taking care of them when they're hurt or sick, and even taking on and defeating an Ultra Beast in one on one combat because it hurt Jessie and James and broke Meowth's heart, overall being the best parent any of them have ever had (and in Jessie and Meowth's case, the only parental figure they've ever had). Unfortunately, Bewear has the flaw of being very clingy and often comes to take the TRio home unannounced, often ruining things for them like competing in a sports competition or even stopping them from nabbing Pikachu after they won a fair and square battle against Ash.
But what why would a Bewear decide to put so much effort in taking care of these random humans and their taking cat you ask? There were many theories that this Bewear was a mother bear that had lost her own cub/s in tragic circumstances and had taken the TRio in as surrogate children (Think Kala from Tarzan). This theory was confirmed in SM 96 when the TRio met a Stufful during an attempted raid on the Aether Foundation. And
Needless to say but I love these bears so much and I hope to see them in Galar.