There are some actual good reaction channels, where they actually add relevant commentary and such. One I have been enjoying is Warp Reactor, love his break downs and medium dives after the video, he does a lot of shows like star trek, Babylon 5, The Orville, and many many more. T. Folse Nuclear is a nuclear engineer and reacts to a lot of sciency stuff with his background. There are a couple more I watch but mostly many of them are questionable content farms