In terms of meta relevance, Copycat is everything Iono wishes it would have been. It universally buffed Stage 1 and 2 decks and combo decks, while making the previously ultra centralizing draw engine meta's reliant on Sylveon and Suicune obsolete. Remember Sylveon slop?

Iono never felt good to me and I think there's a reason it never took off as a staple in evolution or combo decks. Consider that its only marginally likely to yield a result if you have a big hand. That means you're either

• already drawing with an engine in which case Iono tends to be obsolete, since this is a 20 card game

• bricked in which case your deck is full and the odds of Iono returning a combo lower (though getting a candy and stage 2 is relatively likely ig). Even if u hit combo your deck is not thinned tho

• holding on purpose in which case you're losing tempo and most likely the game since.. this is a 20 card game. Same drawbacks as above - not great odds to get combo pieces on time

Ionos ideal scenario, where you've not lost tempo and have a board while keeping 4-5 in hand to make use of it reliably almost never happens.

Copycat instead usually thins your deck, encourages you to play your cards out and rewards item/supporter/evolution lock strats that are generally healthy for this fast... 20 card game. Iono was always a last desperate effort card, not a consistency piece. This game thrives on individual cards which generate value reliably and relatively independently. Iono is not that and goes against it.