I agree for the most part, but it has been implied throughout the series that Pikachu would be EVEN stronger as a Raichu, but as you said, that doesn't have to be the case necessarily since Ash probably has the best Pikachu that exists lol.
Thanks for this which is exactly what I was saying but that guy was ignoring in favor of some weird headcanon he insisted I had.
This point is only mentioned by those who think "Rationally" just like the previous poster. This concept simply doesn't apply in the anime.
One noteworthy person who tells Ash this is Paul; one of the most rational trainers in the series.
Yes, it is rational to assume that an evolved Pokemon will always be stronger than a Pre-evolution. It is also rational to assume that a Pikachu with 2 Electric attacks + Quick Attack + Iron Tail would have no chance against a Gastrodon. Same goes for several other scenarios of Ash's battles where he's always used a very irrational matchup and won.
The simple point is; the previous commenter keeps spewing some rational construct from the games and is applying it to the anime which makes no sense.
The anime simply has no rules. The writers can scale Pokemon to be however strong they want. Saying every Pokemon has a limit in terms of strength is completely false.
Lets say Ash's Pikachu evolves to Raichu. The writers could easily create some concept saying that as Pikachu, it is able to tap into 100% of it's innate power and be much stronger however as a Raichu; it can only tap into 70% of its power so it will never be stronger.
I mean yes, all this seems bs when you consider the games and look at it from a rational Lens. However, the anime has always pulled bs like this.