It’s really not! It just seems that way because of Sturgeon’s Law. We talked about it here. And here are some more off the top of my head:
Alraune (1928), Frankentein (1931), Dirty Rotten Scoundrels (1988), Cat and the Canary (1939—I actually prefer the 1927 version but I’m in the minority).
For uncredited remakes, you also have Alien (1979), Raiders of the Lost Ark (1981). Or, hell, Evil Dead 2, which is a remake of Evil Dead (1979) (and some people like the 2013 remake more). I’ve always thought Predator (1987) was a remake of the mostly forgotten Without Warning—down to Kevin Peter Hall playing the alien in both. Oh, Apocalypto and The Naked Prey are shockingly similar but the former is better.
For remakes that are decidedly different in character (and arguably not remakes, therefore, even though they have the same characters and plot points): High Society, Airplane!, Little Shop of Horrors (1986).