Your claim was that Colorless Pokémon are prevented from seeing success because of a lack of Energy acceleration. My claim is that is not the reason why they aren't seeing more play, and to prove it a counterexample is all that is necessary. Pikachu ex is one of the best decks without Energy acceleration, so it must not just be a lack of acceleration that is holding Colorless Pokémon back—it must be something else. That is all I intend to establish.
No, my claim was that Colorless Pokemon are missing from top decks, because they cannot abuse the cards that make those decks good. It is a meta statement, not a design statement. Even Pikachu ex denies Colorless Pokemon their space, because it only counts Lightning Benched Pokemon. Otherwise it'd probably run Porygon or Ditto.
In terms of design, I have simply not considered "overtuning to the level of Pikachu ex" as a serious suggestion. It was my assumption that we are trying to operate in the realms of good balance. Colorless Pokemon are generally allowed to hit above the curve because of their lack of Type advantage, but in this space they were overtaken by Pikachu ex and Starmie ex. They can also be used to provide versatile support effects but, again, Type-restrictive effects make it harder to include them.
This is the discussion that my previous comment leads into—why is Pikachu ex successful but Colorless attackers aren't, despite them both lacking Energy acceleration, and why is a Mewtwo ex successful with a 4-Energy attack. You state "the main number that matters is the amount of damage a Pokemon can do for the amount of Energy that needs to be attached"—that is missing half of the picture.
The number that matters is the average number of points the attack gets you each turn—and that counts the turns and resources you have to spend powering it up. If an attack costs 10 Energy and does 100 damage, that card's attack is not weaker than 3 Energy for 100 damage as long as it is equally easy to get 10 Energy cards on the one Pokémon as it is to get 3 on the other. Type-limiting Energy acceleration allows the game designers to balance this on a type-by-type basis.
I think this statement is pretty easy to instinctively understand as not true, but I understand the point it's coming from. For a competitive player, if a deck that loads an overtuned attack from hand is perfectly balanced against a deck that uses overtuned acceleration to load a regularly-costed/overcosted attack, then everything seems fine. The consequences of designing a game this way are a separate matter.
On the side of overtuned attacks, it all comes down to numbers. If you want your baseline to be 1-for-10, or 1-for-30, or 1-for-50, all of that is fair as long as the cards you design are kept more-or-less to that baseline. When you have a card that sticks out of that baseline like a sore thumb, the correct answer is to nerf it, especially in an online game.
On the side of overtuned acceleration, it separates the game into "haves" and "have-nots". Even thought decks might be known for their attackers, it is really the acceleration card that is the star of the show. You're swathing away any deck that doesn't have access to this acceleration. The answer here should never be "hey, lets then make those cards horribly overtuned, so they can fight acceleration decks", because you are closing your own design spaces, where you're constantly threatening that these attackers might find a support card they can abuse.
The bottom line is - there is actually no upside to basing the game around acceleration, instead of attaching the Energy 1-by-1. It doesn't provide variance - the game so far has not proven this to be the case, rather showing that it's a zero-sum game; it makes the game more similar by detracting from other strategies and set-ups; and it takes away deck space that could be used for more interesting and strategic effects that actually interact with your opponent.
If 3 Energy for A damage on a Basic Psychic type Pokémon is equivalent in power level to 3 Energy for B damage on a Basic Dark type Pokémon, that doesn't mean A and B are equal. That's the advantage of restricting Energy acceleration.
That is actually a disadvantage - you're straining your design and you're closing your design spaces, you're limiting creativity and you're promoting powercreep. This variance is absolutely fun in moderation, and TCGs with Types or Colors do it all the time, but the main draw of this system is allowing the creative players to find deadly combinations, where these strengths compliment each other.
To put it in simpler terms, you are assuming that Lightning hitting way above the baseline is fine, because it lacks acceleration, while Psychic hitting on baseline is fine, because they do have access to it. This assumes that every Psychic deck will use Gardevoir, that Gardevoir will never rotate out (at least without being replaced by an equivalent card), that Lightning will never get any acceleration, or damage buffing, or any other effect that might accidentally push Pikachu above the line. This is a massive amount of assumptions and restrictions to make and the margin for error is extremely tiny. No designer worth their salt would entertain that.
There are thousands of combinations of possible archetypes in TCG Pocket, and the reason they don't all see play is because they're not all equally powerful. If you un-restrict Energy acceleration effects, it's at least near equally likely—and I think more likely—that that would increase the disparity between decks, not decrease it. You can play Mewtwo ex with any number of partners right now, but the one that is the best sees all of the play.
Yeah, and they're not powerful because they don't have access to acceleration and they play by the rules. That's what a "have-not" does.
Mewtwo ex is definitely not the star of the Mewtwo/Gardevoir deck, which is why people are theorycrafting replacing them with Mew. I'm not convinced, but either way, it's the enabler that makes the deck, not the abuser.
Just because something can be done to improve the format in the present does not mean that it would be a positive change for the game in the future. The fact that we even have as many viable decks as there are with a cardpool this small should be viewed as a positive, not a negative.
Improving the format is just a side-effect. Cards like Misty or Moltres ex are obviously not healthy for the game, but removing Type-gating would still be a global improvement for all the aforementioned reasons. The amount of top decks is okay-ish - Pikachu ex is clearly above the rest - but it is, as always, the disparity between the "haves" and "have-nots" that the designers struggle with.
