Not all the old classics were very long. Casablanca only clocks in at 102 minutes, comparable to anything today.
What are you defining as "nothing much happens"? Are you into special effects, car chases, explosions, or gunfights?
Because otherwise the classics have something going on all the time if you're willing to find it.
Most of what happens in those classics can be found in serious dramas and independent films today. Emphasis on character, conflict between ideologies and personalities, and such.
But some older films also have some pretty stunning scenes that still hold up. Spartacus has some great battle scenes, Ben Hur has the chariot chase, and Lawrence of Arabia has some stunning cinematography and a pretty tense desert crossing, and those are the things just off the top of my head.
Don't believe everything on the Interwebz! A duck's quack DOES echo!