Yes it's true no whale just get first place in a season just from the cards he bought, but somebody who have no max-level-cards can be so good in brain as he want he won't have any chance to get a good place in the leaderboard. So only people who invest much money or rent cards to play have the chance to get at end of season in front of the leaderboard.
This point is other by Steemit: You need not to invest a big sum to be able to write an article who many people vote.
But the other side of the coin is that what you write must be interesting for the people to upvote - this point is important ... whose bread I eat the song I sing ...