Crystal Mind

Fairy is a stronger defensive type, but Absol's problem often isn't its defensive ability, it's speed tier. Moreover, the base form's physically oriented, and Fairy has really bad physical options, while Dark has priority to solve the speed tier. I don't think it would really boost Absol's utility solely based on type.

Dark/Fairy on mega, by contrast, could be tremendous, especially considering that Dark and Fairy is a fairly solid powerful combo for offense. The mixed offense would allow it to push special, which packs Moonblast and Dark Pulse, and gets its superior coverage. It's just an odd stat spread beyond that, given that physical attack doesn't get quite the same benefit.

Honestly there are two issues here, but they intersect and it depends heavily on which one is being prioritized, and how well the goal is oriented toward that.

By main game viability, most Pokemon are fine. But there are obvious and clear gaps in power and utility. Bibarel is not going to do as well as Garchomp, for instance, even in base game. But it's not as clear cut as just stats and ability. I've repeatedly talked about how absolutely garbage Hydreigon is in Gen 5's main game, compared to something like Durant, who is RU but honestly an insanely good pick for the E4 that needs minimal investment.

Under the paradigm of main game utility, having shittier Pokemon does serve a purpose. There's variety, but you may have to do something different to make it work. Oh, you want to run Delcatty in Emerald? Good luck...unless you're doing Calm Mind and have Iron Defense/Double Team Mawile, then you can do some nonsense against Steven's fight. Or maybe you just love, say, Ninetales. Ninetales is not good at all in Gen 1 or even FRLG, but with the investment she packs enough neutral utility to contribute in endgame despite how disadvantages she is. In essence, the choice of Pokemon becomes your difficulty modifier: instead of selecting "hard mode," your harder challenge is natural to the system, you just pick lower order Pokemon or refuse to evolve. In this scenario, it can be frustrating when something is too weak (Ledian, for instance, having virtually no use), but it's far less damning because now there's a project and an appeal to doing something ridiculous.

But that's not really what Pokemon focuses on. They focus on competitive. It's been their central concern since...well, XY at the absolute latest is when it trumped main game experience, though I'd argue the trend started in Gen 3 with the adjustment to EVs, which weren't as hindered by the new Doubles format they were selling as the new competitive format.

Given the competitive angle, you run into separate problems. On the one hand, yes, everyone wants perfect balance, for anything to be viable and useful. This is pure fantasy. You can argue that they could be doing better, but there will never be perfect balance. Some things will always find a way to stand out as stronger picks; just look at Smogon's odd meta picks, like the "everything has 100s across the board stats" and how wildly this influences rankings, but still creates a meta. There's no possible way to balance perfectly.

But it is staggeringly easy to figure out when they didn't even bother trying. "Oh my god, what a cute little fox, its tail covers its footprints while it steals things how darling! Shame it's an early game creature with shit stats and movepool and sub-optimal ability." Like you can feel the disregard. When you build out your focus of your games as the next link in competitive, rather than an in-game experience, the recognition that some things are doomed to suck feels bad. Like you assholes know that competitive is the endgoal, it's the entire reason you refuse to allow multiple saves on a single cart and make such a big deal about "Your adventure" as a singular unique experience each generation; if the goal isn't replay value (and it never has been), then it's about the post-game competitive experience and the game is intended to die on transition to the new generation, or even new game. So why is it that we're still doing this filler nonsense of an early game bug that has never had a modicum of competitive viability? You can't do something different for this particular archetype? It just gets old, like having every goddamned pseudo-legend be Dragon. Do something different! It didn't even start this way!

But more to the point, it feels that way in part because it is that way. Like, statistically, how big is a top meta set? Smogon's SV OU meta has 41 Pokemon. Out of over 1000. Even cutting that number to half based on evolutionary lines, that's less than 10% being relevant. So by numbers, most people's favorites are trash. But then you filter it down a bit and it's even easier to pinpoint. Is your favorite a legendary or a pseudo-legend? It's probably fantastic. If your favorite definitively cute in design? It probably sucks. Like you can tell viability in most situations by type alone, given how often stronger abilities and expansive movepools tend to correlate to specific types. Are you a Bug or Ice type? Enjoy zero coverage, shit stats/stat allocation, and poor abilities, bitch. Are you a Dragon type? Enjoy massive stats, perfect allocation, potent abilities, and unbelievable coverage.