I never watched the second season, which I understand not only broke up the movie, but added some minor (insignificant?) scenes. Watched season 1, then the movie, then the next couple seasons. I haven't seen the latest season, or the new movie.

I've had non-anime friends see the new movie and they said they were fine with not knowing anything about Demon Slayer going in. Still, I'm not going to watch it until I see the latest season. Apparently, the movie and two others will finish the series.