The final nail in the coffin will be the introduction of 4K Blu-Ray players in a few months.
If someone's really got a bug up their butt about wanting the very finest video quality imaginable, and the jury's still out on that, why settle for overcompressed, problematic streaming that you have to pay a fortune for when you can just buy a 4K Blu-Ray disk and get HEVC at 50mbps+?
The disk model for distributing video won't last forever, but audiophiles are still listening to vinyl LPs long after everybody else went to CDs, then MP3s. The market for disks won't be enormous, but I'll bet most folks will want a few titles in 4K just to justify the new TV and to make their friends ooh and aah.