When I watched last night's episode of the Simpsons, it made me think of the problem with very long shows. So the Simpsons are on season 23, 23 years of the Simpsons.
Think about it like this : 496 episodes have aired. That's more days than in a year. Nobody gets older so it's a sort of weird time warp that is operated where nothing ever changes.
But that's what sitcoms do. They keep us in an unaltered reality where time has stopped. Sure, the seasons change and the family celebrates different holidays and keeps up with the times with technology, cultural and political references.