The whole "reaction" genre has exploded in the last year or so; there are dozens now.
With some I suspect it's a long-term troll; feigning utter ignorance of the Beatles for instance. And there's one dip****er who just carries on an endless Beatles troll project: obtusely contrarian long-winded and faux-artistic reviews of all their albums. If you hate the Beatles, I don't care, no law says you have to like the Beatles. But doing ass-backwards "reviews" of everything they did just to lampoon fans' pomposity, has to get monotonous after a while.
I probably watch J_aka_J and India Reacts the most. A couple of years ago I used to watch "Squint Reacts" and "Hip-Hop Head/Millennial Reacts," but both of them seemed to quit abruptly -- no advance notice, nothing about less frequent or numerous reviews -- they just stopped. And that's OK too -- no law says you have to make reaction videos. If it's no fun, walk away.