I'm not saying only good movies come from the 70s. Just that good movies come from all time periods. Apart from Interstellar that's a good list IMO, but excluding Interstellar and Dark Knight they are all from the 80s & 90s.
Discussion
I agree with the first part. Good movies come from all eras.
But there are more good movies that are recent apart from interstellar and dark knight
Like I said in the first part, good movies from all time periods. Post 2000 has a lot more remakes and sequels, and less original films I think, but there is still a lot of good stuff out there.