Can we just take a moment to appreciate how difficult these games are? Even when I was a noob in Pokemon, trainers and such never did give me as much trouble as in Sun and Moon. Totem Pokemon are though, smart and capable to sweep entire teams through their battle strategies. Don't get me started on Totem Lurantis, when it summoned a Castform I lost my shit upon realizing what that entailed.
A special mention goes to the E4. If they feel they can knock you out they won't waste a turn using a full restore if their pokemon has low health. And then there's the final challenge, where I barely made it, with only one single of my pokemon at half health. It was the thoughest battle I've ever had.
The spike in difficulty is real, GF has finally delivered in that department.