This was originally posted in the r/Pokemon subreddit, in which much discussion was had. It has been backdated to match the original's date of posting.
I've seen a lot of people talking about how Pokemon hasn't been coming out with good games recently, so I started wondering... what kinds of changes should they make to go in the right direction? Of course, you can talk about making a compelling story with better environments, etc, but one concrete thing to improve the main game mechanic the games revolve around--the battling--would be to switch from defaulting from single battles to double battles. One thing that I feel like removes a lot of tension from the battles in games is that they often follow a predictable flow: knock their first Pokemon out, the game tells you what they'll send it (which I know you can turn off but still), switch to a Pokemon that is advantageous against theirs, knock that Pokemon out, rinse and repeat until you win handily.
Think about it--what turn based games released in the last decade aside from Pokemon only let you deploy one character at a time? I don't have the biggest wealth of rpg knowledge, but there's a good reason why I can't think of one. Sure, with Pokemon you can customize your team a lot more than most games, but the fact of the matter is a lot of the unknowns are eliminated and a lot of strategy just isn't there when you have only you and your opponent on the field.
If we want further proof that doubles are better than singles, we can look to the competitive scene. Sure, not everyone that's casually playing through a Pokemon game is a hardcore tournament-goer, but it's a fact that competitive players want to play a game that is as interesting and deep as possible, and I feel it's the general consensus of these people that double battles are simply more interesting and deep than single battles.
I have other opinions of course, but I think this is probably the biggest thing I would want to see in any future games. As it is right now, I don't feel like my brain is being engaged all that much when I battle in the main story of a Pokemon game, and it feels like any losses I incur are due to just not having good type matchups as opposed to my mistakes in battle.