Earlier quoted context omitted.
Plex and similar software are pretty popular. Not to mention most phones can 'cast' to all those devices. Both my smart tv's even have USB ports.
It's kind of funny the number of people responding with Plex. I've used it for years, and it's an effective piece of software but it requires running a server in your house, managing storage, etc. etc... there's no way the average user is interested in doing that.
For a decade now, Plex runs on any Windows / Mac / Linux device. It'll run on a Raspberry Pi. NVIDIA Shield. Western Digital's My Cloud NAS products (from $139 w/ 2TB). QNAP. Synology.
The main obstacle for "average" people is just knowing that Plex exists.