I use Pluto for this. Quick download, no sign up required, and tons of topic-specific channels to switch to. I put it on all my devices and don't even worry about it.
Google TV also has a "Live" tab that collects all the live channels across all your apps and puts it into a TV guide grid. I've installed Fubo and Tubi and others just to build out my TV guide.
>>pests+(OP)
I was part of Pluto's launch team. We used to literally just be 95% YouTube embeds that were forced into a live-like experience client-side. Getting simple YouTube or even HTML5 video API calls to work reliably in 2013 was quite a feat. Loads of people still had Flash, mobile browsers were a crapshoot, and I caused many many thousands of early Amazon Fire TV hard restarts due to crashing their (kernel?) video decoder somehow.