Why do people record people reacting to other people? It's about as interesting as those utterly pointless unboxing videos. Oooh look! Someone removing something from a box!
I understand what you mean, but they can really work wonders.
The better comedy reviewers make you appreciate or really like some sketch show or comedy performers where you went "meh" or wouldn't watch thru them when first aired.
Their genuine laughs, their appreciation of the idea, writers and the sketch performance, plus their interrupting comments that add rather than hinder. There are only about 5 or 6 channels who I will watch the same sketch or piece with just to enjoy different hits from people I like.
Three channels at least are very, very good.
Mine are mainly American (or Aussie) reviewers watching older UK stuff they are not used to and are very generous about in their comments.
The other channels are faking it purely for donations, or have no character or personality. I still often find one or two good new channels though where I like the reactor. That's lockdowns for you.
I still won't watch some shows or performers they review regularly. We all have our dislikes. However at least two shows or comedians I didn't like I now think are really talented geniuses because of these top reaction channels.
Philomena Cunk in the UK for example is an odd though very well written comedy/fake documentary series, in part interviewing real experts, without laughter or punchlines that mostly fails on air but comes alive in review clips, but there are many badly edited compilation clips out of context they work from which ruin it again. That show has now been taken on by Netflix I think, along with Diane Morgan who plays Philomena. Her accent is not for everyone.
Getting a full show to react to without falling foul of copyright can be difficult for them too.