AI in Pokémon games

As with all video games, Pokémon has opponents with AI that use different moves on you. But more often than not, sometimes opponents make highly questionable moves, like repeatedly using moves that lower your stats, or moves that are not very effective, or god help you, using moves that can't hit you. It can be hard to compare AI between games, but how would you? Are there any main series games you would say have opponents smarter than in others?

To name one, some people have said that in XY, the AI got worse, but I don't completely agree with that. There were trainers that would repeatedly use a move that would be super-effective on me (like the Fighting-type trainers in Reflection Cave, and sometimes Ace Trainers/Veterans), but we also had opponents that weren't exactly bright (in Victory Road, a Fairy Tale Girl's Florgés used Petal Dance when I had a Houndoom out, I think).

How about you? Are there any games that you think trainers are better or worse in than others? Discuss.

I always thought that the games AI was purposely designed to be... well pushovers. This is after all a game designed for children as young as 6 years old to pick up, play, and enjoy.

Whenever I want to see complicated AI, I go to the "Battle Frontier" permitted that there actually is one within the game I'm playing. That's where they hide all the intelligent AI. Almost all the games have minor intelligence within their AI when you're looking towards the more competitive PVE within the game.
I remember when I was playing B&W, although it was a lame competitive addition, the Battle Subway had some pretty intelligent and creative AI, some so much so that they were practically cheating.
Although the battle subway was repetitive and annoying, I still have to admit, it had some of the most complicated battle patterns and team designs I had ever seen for most of the competitive aspects of the AI within the game. Sometimes I think that the badly designed progression within the battle subway was made as a prototype to test how far they could push their competitive AI. (I actually can't remember exactly, but was the data for the various trainers within the Subway pulled off of the internet? I seem to remember that... I can't remember if it was previously designed AI by the game creators, or if it was based on certain saved player information from the internet? Been so long since I played that game.)

The serious AI that has always been entertaining and sometimes near impossible to predict, has always been any NPC trainer designed within the battle frontier. Sometimes you can gain an advantage over them if they are type focused, but even then they often follow relatively competitive strategies, making them often exciting to fight against, and a very interesting and entertaining challenge.

I'm actually trying to learn about the Battle Frontier in the past games, in order to attempt replicating and expanding it within a hacked game. The Pokemon games in general need more competitive AI (IMO).

The AI for other trainer class expect gym leaders, elite four or gym leaders are bit much different.
The opponents in battle chateau switches pokemon that may immune to ground-type attacks, use a audino with simple beam/entertainment just to remove your mon's ability with healer/simple or use a status moves like toxic or stun spore.

My case; AI these days are not much or least creative (use super effective move, status or switch) I wish AI would be more interesting and creative with their tactics