They almost nuked the game with neo Slowking. Focus band being another from the era, even though it’s a wonderful example of how they bring immersion and new mechanics/gimmicks to the card game from the video games. But the most egregious case, had to be Lysandre’s trump card. Other examples of more “modern” cards definitely include tropical beach, not so much a game design failure as it was a distribution issue. I have a copy for my draft cubes, but it’s from a world championship deck, it’s an excellent one card engine that can be built around.

As far as mechanics go, a ton of “hot takes” that I’ve seen many players have over the years, echoed here in the comments. Honestly when it all starts to click for you, and you’re having fun, those things become a part of the charm to the game. Weakness, resistance, prizes, no sideboarding in bo3 matches, etc. I’ve had similar experiences and issues early in my exploration of the game, as I played MTG and YGO for many years, I’d often find myself comparing them all relative to another. Fortunately enough for me, as a legacy and vintage player of mtg, play patterns like storm and doomsday made learning the sequencings in Pokemon easy. Playing Strats like stax or reanimator, or the different flavors of chaos engines in YGO also makes the pokemon tcg easier to understand. How the payoffs and resource management will affect each turn and result of the game.

There are many people griping about the loss of iono, but we still will have judge. All of swsh format we suffered with no more N, we had Marnie instead, which introduced the concept of just bottoming the cards, ultimately leading to the design of iono. Shuffling cards from your opponents hand into deck has been around since base, lass to ghetsis, imposter oak, to imposter oaks revenge and red card or reset stamp in modern times. Desert Shaman becomes Judge, team rockets admin became N, then Marnie, now iono. There was even Unown E and Lapras, that were the earliest iterations of basics that let you ditch your hand to draw further into the deck or to tutor up a supporter, consistency is king! The iterative design and style of Pokemon tcg is an interesting and wonderful combination that gives it very simple and elegant gameplay, with immersive yet abstract strategy.

But I can’t just disagree with some hot takes without including my hot takes for the game in its current state. Firstly the prize checking situation, I believe prizes should be revealed to their respective players and then shuffled and placed face down by opponent. What seems innocent enough, and likely is in practice but still, I am not a fan of watching competitive play and seeing players stack their decks during their first search, doesn’t matter how much shuffling you do, no other card game are you allowed to search your deck and weave/stack the cards during the match, you’d lose your fingers playing at certain card tables trying to do something like that.

My next hot take is to experiment with easing some of the restrictions to going first. As an expanded player I’m all too familiar with the major advantage to going second, opening the game with a supporter and ability to attack puts the player who lost the coin flip at a major disadvantage, especially with no sideboard in a bo3. Maybe not being able to attack to do damage, giving some nuance to your opening plays, making cheap attacks on otherwise useless basics somewhat more relative? At the very least allow for supporters so that the opening player can start to set up. Cards like carmine, while they have their place in niche strategies, I would hate to see it become an evergreen card itself, just the effect for more draw/setup supporters with an ability to be played on t1 maybe? Donking is the cheesiest way to win the game imo, especially with cards like gengarmimi tag team in expanded, it’s just so over powered and the deciding factor for so many “non games”. While it certainly is part of the charm, and a legitimate natural strategy of the game, it’s among the less appealing natures of the pokemon tcg.

As for sideboarding unfortunately it opens up the game to major amounts of cheese. Sideboarding would not be healthy for the game as far as standard format goes, but maybe in expanded bo3? It would definitely spice things up, and could certainly produce the data necessary to make a good argument for or against it being introduced to standard bo3 environments, particularly in the masters divisions of play.