Do New Evolutions Actually Help the Pokémon that Need it Most?

Can we please stop "fixing" Johto Pokémon? I get that a lot of them have been left behind over the years but at this point I'm just starting to wonder why they even bothered creating a whole Generation if later they just say it's not good enough... I don't hate all new evolutions or form changes of Pokémon, in fact I like a good majority of them, but I can't help but think if they're really succeed in the job for which they were supposedly created...