Citation needed; the top X on IMDB has a mix of recent (2014's Interstellar) and older (1972's The Godfather) films in their top ranked films: https://www.imdb.com/chart/top/

Of course, rankings on any platform should be taken with a grain of salt; if you like the film you like it, can't argue with taste or personal preference. Ranking tries to apply an objective fact (a number, an expert's say-so) to an inherently subjective question (did you enjoy it).

Citation I dont have but I analyzed score dumps before from imdb and there was a clear correlation between recency and higher score over time