I say that prequels and sequels are worse because they, most often, ignore the point of the original story, and are forced into a creative box, trying not to contradict. At least if you remake or reboot something, you can give your own spin or interpretation or reimagining on it.
Or, at least, they should. Reboots and remakes are telling the same story, and while that's not necessarily a bad thing and some reboots and remakes can add to the original and can even surpass it, you've seen it before. With sequels and prequels, it can just retell the same story, but in sequels you can see how the characters and the world has grown and changed, and in prequels you get context. It adds more to the story. A lot of reboots or remakes are just there to regurgitate iconic moments. And that's not to say sequels and prequels don't often just follow the same story, but they're required to do something differently.