One of the reasons I’m a physical media collector is that I always have access to the DVDs/Blu-rays that I own. I’m not subject to the whims of streaming services deciding which movies/TV series I can watch.
Lilies is a good example of this. It ran for but a single season (just eight episodes) on the BBC. As far as I can tell, it is not available to stream anywhere. Yet I can watch it anytime I want because I own it on DVD.
Not that I want to very often, but I could if I wanted to right now. Anyway, you can read my review of the series here.
themidnightcafe.org 
I whole-heartedly agree with your thoughts about the benefits physical medium versus streaming. This is equally true for music, where albums can be removed from streaming services without any notice (or never to be included to begin with). For example, several CSN(Y) box sets are either not available on streaming services or are available only in truncated form. Neil Young’s third installment of his Archive series is only available in a sampler form. Bottom line: if you own a physical copy, you can decide what you want to listen to. Otherwise, you are subject to the whims of Spotify, Apple Music, etc.
Yes! Even if you “purchase” a digital copy the companies can still delete the music/movies/TV shows on a whim and you completely lose them.
Also my Internet services isn’t great so it often slows way down during peak hours. On those occassions I can just grab a DVD and watch what I want without dealing with buffering or any other problems.