There is a data miner who discovered that the Pokérus isn't in the game. It's a small detail on its own. As time goes on, Pokemon games are getting less weird.
The strange virus needs some explanation. The Pokérus had a low chance of infecting a pokémon. The shiny pokmon have a base one in 4,000 chances of appearing. The Pokérus was beneficial even though it was presented as an illness.
You need to understand effort values as well. There is a reward for defeating an opponent in a battle. In-game, EV's are rarely referred to at all. They don't have an effect on the casual player. Your own pokémon will grow in a balanced way if you battle a variety of them.
EV becomes a useful tool when things are competitive. A physical and a special attack stat are included in the price of pokémon. Individual pokmon have a natural affinity for one or the other, and their moves can only fall into one of those categories. Competitive trainers will focus on gaining EVs in just one form of attack in order to avoid splitting them.
It was a strange thing when it first came out.
The pokémon used to gain double EV quickly. The players who wanted to get the strongest possible pokémon would try to get their friends to join them. It wasn't a rare occurrence, but it was a part of the game.
It doesn't have much of an effect on the game. A small group of players were affected by the Pokérus. Even if they hit that one in 20,000 chance, the casual player wouldn't notice anything. More and more ways to get powerful teams have been introduced by the games. The time and effort of breeding and training powerful monsters is not required for players who want top-end battles.
The story of the Pokérus mirrors a shift in the games as a whole. It was a strange thing when it first came out. There were rumors about Red and Blue being hidden under a truck and that anyone who heard the music would die. There were times when the rumors were genuine. You can use your fishing rod on statues as if they were floating on water, certain characters can disappear and allow you to sequence break, and glitched pokémon like MissingNo can be found in the game.
The weird, almost impossible to reproduce, potentially scary thing that happened when Gold and Silver was introduced was the same thing that happened when the Pokérus was introduced. The internet and data mining made it well-known. Along with its mechanics and uses were revealed. It became a way for those who wanted it and a way for everyone else to learn something.
Many of Pokémon's quirks can be said to be similar. Most players wouldn't see a recoloring like the shinies that was once a rare occurrence. It might become a symbol of extraordinary luck to brag about with friends if they didn't know what was happening. There are a number of ways to get shinies nowadays. You need luck, but not as much. Perseverance and brute force have replaced it.
It's a shame that the games have lost the joy and quirk of the past.
Quality-of-life changes have been made due to the existence of these grinds. If you went to the day care center, you could occasionally find eggs that were weird. As eggs became central to various high-end mechanics, they became easier and easier to get. Eggs can be hatched in minutes if you have the right sandwich powers.
There is a mechanic that causes friendship to evolve. It is only vaguely mentioned in most games, with a single NPC somewhere in the world giving a broad response as a hint. Without a clear understanding of how it works, a pokémon suddenly evolving after you have had it for a while and use a lot is a brilliant surprise. It seems that the creators of Pokémon have responded to the fact that it is easy to find out how to increase friendship levels. There are a few sandwiches that can do the trick in the two towns. It could be a surprise, but only because of how fast it happened. You don't have to wait, travel around, battle, or get closer to your pokémon.
The loss of joyful surprises in the games is a shame and not one that the company can easily avoid. The data miner discovered that the Pokérus isn't present in the game. Within days of the game's release, all the secrets will be revealed, and people will begin to get what they want.
That is not the case for the Pokérus. It wasn't clear why it was removed, but it had already changed from its initial iteration. It used to be strange, unexpected, and inexplicable, but now it is understood, common, and easy to exploit.