It's mostly garbage. Has its good moments, like in certain Platinum or BW2 battles, or some of the Gen 7 Totem battles that were well designed, but other than that it's disappointing. It barely makes you think or strategize at all.
Basically, you need to add at least a few rules on your own to prevent the in-game difficulty from becoming a total joke. I don't know, perhaps some players do enjoy destroying everything with zero effort but I honestly got so bored years ago that it made me lost interest in the franchise for a while. It was self-imposed rules, changing my battle style to set, and rediscovering the franchise thanks to rom hacks and fan games that did make me use my head, that revived my interest in Pokémon games.
I think the difficulty is by far the worst and most poorly handled aspect in the franchise, you have the in-game that's a joke unless you nerf yourself with extra rules, and then you have things like Battle towers where you'll get completely destroyed unless you're willing to waste a lot of time on perfect IV breeding, EV training, and all that stuff to build a competitive team. There's just no fair middle ground, other than finding your own way to customize your experience for you.