I have gotten more enjoyment out of watching some silent-era movies than modern release movies. Particularly, the 1916
20,000 Leagues is great. In general I don't think there is any real relationship between the age of a movie and the quality of a movie; quality movies are more or less evenly distributed through time. Sometimes film makers strike gold through some fortunate coincidence of inspiration, talent and luck, and most of the time they don't. And yes, that means most old movies aren't good; but most new movies aren't good either.
The passage of time doesn't play a role, because even though individual directors/actors get more experience with age, they also age out of the industry and get replaced with new guys. And besides, it is very often the case that movies get worse as a director ages. Compare The Godfather to anything Francis Ford Coppola has made in the past 30 years. Or Michael Mann's Thief and Manhunter to anything he's done in the past 20. Or Ridley Scott's filmography. There are many examples like this; experience counts for something but old men often lose their edge.