How many universally-regarded "great" movies are there? Maybe it's just bizarre to think that every decade will produce one of the 10 or 20 greatest American movies: Casablanca (40s), The Godfather (70s), Raging Bull (80s), Citizen Kane (40s), Vertigo (50s), Gone With The Wind (30s?), The Empire Strikes Back (80s), The Shawshank Redemption (90s), The Searchers (50s), 2001: A Space Odyssey (60s), Apocalypse Now (70s), etc.
Then there are non-American produced films that are worthy of being all-time greats: Shichinin no Samurai (Seven Samurai), Bronenosets Potyomkin (Battleship Potemkin), Tōkyō Monogatari (Tokyo Story), La Règle du Jeu (The Rules of the Game), Ladri di biciclette (Bicycle Thief), La Passion de Jeanne d'Arc (The Passion of Joan of Arc), etc.
The 2000s had some great movies: Memento, The Dark Knight, The Incredibles, The Departed, No Country For Old Men, Eternal Sunshine of the Spotless Mind, There Will Be Blood, Children of Men, Mulholland Drive, LOTR: The Two Towers (more like all three films together, but if you have to choose one...), Crouching Tiger Hidden Dragon, Silver Linings Playbook, City of God, etc., that were each worthy of consideration among the best 10-20 of the decade, last twenty years, maybe quarter century...but not necessarily of all time. That doesn't mean they aren't great.
Likewise with the 2010s: Inception, Django Unchained, Manchester by the Sea, Gravity, Inside Out, Boyhood, Dunkirk, 12 Years a Slave, Zero Dark Thirty, Birdman, The Big Short, The Wolf of Wall Street, Argo, Toy Story 3, Skyfall, The Avengers, her, American Hustle, etc., again worthy of consideration for great films of the last 20, 25, or even 30 years. Again, not necessarily of all time. Still doesn't mean they aren't great.
It's kind of like the thread about the the greatest basketball players of all time. James Harden and Russell Westbrook are great, but are they even top 50? Probably not, but that doesn't mean they aren't great. They're easily top 50 of the last 10, 25, and maybe even 30 years, but not all time. How many current players crack the top 50? Lebron, KD, Steph Curry, Chris Paul, Kawhi Leonard? And of those, how many are top 10-20? Lebron and KD? Doesn't mean Steph, CP, Kawhi, etc. aren't great.
Every decade has produced 10-20 great movies.