Each time a new game comes out, it is inevitably compared to all those that came before it. This is even more the case when a large batch of new games is released, as occurs each year around Essen time. If some new game has, for example, an Auction mechanic, then it is denounced as "yet another Auction game."
I believe that such superficial comparisons are presumptuous.
Consider the Area Majority mechanic, which is exemplified by such great games as El Grande, Maharaja, Liberté, San Marco, Aton, Carolus Magnus, Mexica, Mission: Red Planet, and Carcassonne. I own and happily play all of these. None feels remotely like another even though some share other mechanics.
Another way to look at this is to choose any mechanic and find games you like and dislike that use it. If the mechanic alone made the game, this would not be the case at all. With Set Collection for example, I like Taj Mahal, Ra, and Tower of Babel, but dislike Ticket to Ride and Fairy Tale.
Games are more than a list of mechanics. Mechanics must be stitched together in various ways, drive each other, feedback into each other, and complement each other. This stitching provides the sequencing and flow of a game, directly affects the kinds of decisions players make, and can provide tension and conflict.
The simplest rule can completely change the texture of a game. Imagine Quarto! without the rule that you choose the piece your opponent plays. Imagine Medina without the rule that you can't start a new palace of a given color if the current one is incomplete. Imagine Rheinlander without reinforcements.
When I hear about new games featuring mechanics that exist in games I love, I don't dismiss them, I pay attention. Did the designer find some new way to hook things together? If so, don't be so quick to pronounce the game a rehash.