Its all theatre DMX lighting > ola (open lighting architecture) > ArtNet > home assistant.
It's slightly jankier than if I had built a direct ola > Hass plugin but it works quite well
I also only run lighting, and control my Chromecast on my Home assistant - and both are turned off at the power supply when I'm not home, it isn't accessible outside the LAN (except through a zerotier VPN, though I probably should turn that off as I don't use it much)
Nearly everyone I know watches YouTube in some kind or another regularly. Most of them on a smart TV or mobile with ads. I think the amount of people watching youtube regularly is vastly higher than the amount of people just watching it when they get sent one video. Espechially since most people use phones to communicate with others and will watch the Videos sent to them with that device and the original YouTube App.