The Guardian reblogged this analysis of film length, which found, up to 2018, that films were not getting longer:
In conclusion, our intuition was wrong. There is no trend in the movies runtime. The differences are too small to be noticed. We can say that for the last 60 years movies on average have the same length. No matter what criteria we take into account, the result is the same.
I regenerated the three most interesting charts with data up to the present, and it seems like films are indeed getting longer!
It will be interesting to see how this trends going forward.