I think Pokémon (the creatures) have been getting better movesets as new generations have come out.
It also feels like the average power of moves has increased over the years. I'm guessing some of it is due to Z-Moves, which are just moves that are more powerful.
Stat total averages also seem to be rising, partly due to mega evolution.
I dunno if it means Pokémon are overpowered, though. When I play Pokémon, I actually feel most powerful in the early games.
EDIT: There's this old thread from 2010 discussing power creep in Pokémon. Curious how it'd look like now, 13 years into the future.