If everything is nerfed, nothing is.
This is not really true though!
The change from stat experience to EVs means "everything is frailer and there is more of an opportunity cost to mixed offenses" - that's going to hit some Pokémon differently than others and hit some harder than others, not just evenly scale everything
Dugtrio is affected more than average by the inability to run bulk investment because of its naturally low base HP, Defense and Special Defense - Gen I Dugtrio has no less than 1.9 times the physical bulk of Gen III Dugtrio
(compared to modern Dugtrio, Gen I Dugtrio was basically always behind Reflect! this does not magically even out unless we assume every physical Pokémon hit 1.9 times harder in Gen I, which... they didn't P:) and another 1.763 times the special bulk.
The reason I say this is specific to Dugtrio is because Pokémon are affected far less by losing EVs in stats that are already high - let's compare something whose stats lean a different way and are much higher than Dugtrio's, like Blissey.
Blissey was only about 20% more specially bulky with stat experience than it is today
and actually has 10% more physical bulk now because of natures, while Dugtrio may have 10% more Attack to counteract but it may instead have 10% more Speed to deal with all of the other Pokémon that have 10% more Speed than they used to, and so on. In turn, Blissey runs Special Attack (and special attacking moves) much less often in current metagames, but can we assume that means it loses as much Special Attack as Dugtrio lost Special Defense? Well... actually no, not even close! Blissey with free investment only hits just shy of 34% harder with its special moves in Gen II than it does now, while Dugtrio takes over 76% more damage now than before - it does not even out to be the same!
The point isn't that Blissey vs Dugtrio is a specific and important matchup that changed or anything - I'm just trying to highlight how different both Pokémon are from each other in the way that this change affected them. Nerfing everything in the same
way does
not mean nerfing everything by the same
amount and it did hit Pokémon with different stats and in different roles much, much more than others even in terms of raw numerical differences!
I'm aware we're talking about in-game, so this isn't really relevant, but I also want to highlight that Dugtrio was actually a lot
better in Gen III OU than the preceding Generations because it got
something way more important than most of its bulk an Ability
Every Pokémon got an Ability, but Dugtrio's Ability was more important to it than other Pokémon's Abilities were to them
Every Pokémon was nerfed at the same time, but every Pokémon was also buffed at the same time... and that doesn't amount to the same as "no one" being nerfed and "no one" being buffed - it means every Pokémon changed
even more between the two systems and power levels and dynamics shifted
even more between different metagames
Dugtrio got a lot worse in-game
because its big buff, Arena Trap, is a functionally much less useful Ability in-game (NPCs in Gen III barely know how to switch, so its massive competitive buff was irrelevant), while its disproportionately substantial bulk decrease matters a lot more in-game (it was probably always pretty frail in competitive, but opponents in-game are uninvested and do less damage in general, so there are a lot of hits it could live before that it can't now); it lost more than it gained for in-game purposes and bdt2002 was right to identify that as a factor
and that's another thing that's
not true of literally every Pokémon; every Pokémon lost bulk in different amounts and gained Abilities to different effect, which does not make them even roughly the same as before!
Also, even in the hypothetical situation that all Pokémon were affected to the same extent, do you really think that would be the same as not nerfing anything at all? A game where everything takes 25% less damage is going to be way, way different from a game where everything does 33% more damage, and both of them are going to be way, way different from what we have now
The same change was made to every Pokémon, but it's still biased towards some roles and against others
A universally-bulkier metagame is probably biased a lot more towards defensive playing styles but also makes it a lot safer to run setup and sweep, while a universally-frailer one may make stall less viable but makes it that much easier to revenge sweepers and for fast Pokémon without setup to come in and clean efficiently and at earlier points in the game; there is a lot more to it than just "did we raise everything's stats by the same amount?"
There's also the really fun example that LGPE has had two playable metas - a candy meta (close-ish to stat experience but every Pokémon has literally 200 more points in every stat) and a candyless one (candy is banned so Pokémon are outright uninvested in all stats) - and the way these play is
incredibly different; the candy meta proved way less popular to my knowledge because it was so much more difficult to make progress in general (even Rest was reliable recovery on most things because lasting three turns was just easy), while some unusual setup sweepers like Venomoth actually still thrived there because they had a much easier time setting up than in other metagames
On paper, the same change was made to every single Pokémon, but the game was still
different - in your terms, every Pokémon in candyless was nerfed, but it was nothing
like when no Pokémon were nerfed even though "everything has 200 less in all stats" is the only difference that exists between the two metagames
This is also like saying that adding a new held item doesn't change anything as long as every Pokémon can hold it, which is obviously not true (see Boots! those changed a lot about how the game is played, and they benefited Rock-weak Pokémon, hazard control users and defensive pivots a whole lot more in different ways and to different extents from one another)
and this kind of thing is why Dynamax was banned competitively, too - people often ask "how can it be broken if both players have it/how can it make anything broken if every Pokémon has it?" but despite doing literally the same thing to every Pokémon on the surface, it doesn't affect every Pokémon the same way and only specific archetypes can take proper advantage of it (and even if every Pokémon could use it the same way, that wouldn't necessarily preserve existing power dynamics exactly)
I know you're just quoting the Incredibles but still
This kind of mindset makes genuinely huge mechanical changes sound a lot less interesting than they really are :<
But seriously I liked Sigilyph quite a bit when I first played but after subsequent runs; I disliked it due to the damage it could not do. It seemed to be pretty mediocre and possibly somewhat frail(?).
Having decent Attack and being one of the few mons who could learn Rock Slide in Gen 2 made Sudowoodo fairly low-maintenance in that generation (at least for a mono-Rock mon). In the time between then and now? It's fallen so far that it's outclassed by Stonjourner of all things.
High Speed + STAB Body Slam and Hyper Beam is fun to spam Critical Hits with... when the game's mechanics allow it, that is.
