I will agree to disagree.
Some of the newer generation Pokemon are a little iffy.
But you have to take into consideration, there ARE many different types of birds in the world that are quite similar.
There are many legendary and mythical creatures in the real world, more so than that of the Pokemon world.
If I had it my way, Pokemon would have enough legend and myth to back up each continent.
Count Kanto and Johto as one continent with their 251 Pokemon.
Hoenn with its 135 Pokemon.
And Sinnoh with its 107 Pokemon.
And now, Isshu with its whatever number Pokemon.
Just because each new generation seems to ruin the last, you need to take into consideration that it's a different part of the world, with its own legends and myths, different beliefs to those on other continents in the Pokemon world.
Just because Arceus is said in The Legend of Sinnoh to have created the Universe, that is not to deter any other continent from having its own version of a "God" Pokemon.
Mew, for instance, is the ancestor or "all Pokemon".
This basically means Mew carries the genetic code for all of the Pokemon.
Mew may very well surpass Arceus. But we don't have a backing story big enough behind Mew because Pokemon was only getting off to a start back then.
Just as Ireland has Banshees and Chinese has Shang-Yang(Rain bird), Pokemon's different parts of the world will have their own mythological creatures.
Arceus being God is mostly a Sinnoh belief and does not really extend beyond that region.
Mew, in Kanto, is still believed to the most powerful and "God"-like Pokemon of its region.
So take it in your stride and just go with what I go with...
Each continent has its own belief systems, its own myths and legends.
Its own way of telling a story and representing us with new creatures.
I like to take each new generation and take it for what it has given us.
Different stories. Different adventures. Different creatures.
We shouldn't discriminate one against the other.
Although, in the hardest fan, this is a belief not easily taken on.
I've been with Pokemon since Day 1. And I will stick with it to Day Last.
This means supporting the newer generations as they come, no matter what.
But hey, that's just me. Each to their own, I say.