I do agree about a lot of the previous stuff not being filler. Some of it has been setting up characterization and dynamics. You can afford more filler early on in your story so the reader can get used to the characters.
But even then, there are still some that could have been snipped down. We didn't entirely need to have.
For example, I don't really consider much of the latest Leigh build as filler. Maybe some of the dialogue with Charlie but most of that build's scenes served a purpose.
However, some scenes like Lucas explaining the book he's reading in an earlier scene of his route really didn't need to be there to that degree. We could have simply learned the basics of the book to infer that Lucas prefers reading stories for escapism.
My mentality about filler is scenes that don't serve a purpose. Even if a fun scene might be nice to read, if it doesn't serve a purpose it's cuttable. However, that scene might still be included because it serves a purpose tonally or for pacing reasons.