Idk, the cheapest Netflix streaming service w/o ads is $15.50/month. Most Blurays are $10-15. So each Bluray is something like a month of Netflix.

If you watch a lot of movies/TV shows and almost never rewatch them, then yeah, maybe a streaming service is a good option. But if you need multiple streaming services to get the content you want, the appeal of just buying physical media increases. My kids mostly watch the same handful of TV series, so I have cancelled our subscriptions (totaling $40 or so) and now I just buy the shows they want.