I mean they're all similar in that most of them raise the level of your guitar and most of them usually roll off low end from the guitar.
Within that relatively narrow set of constraints though, they can be fairly different. The components that generate overdrive can be quite different, the controls that change different parts of what's going on can do very different things, the amount of boost and filtering characteristics can be quite different, etc.
So yeah there's plenty of reason to prefer any given boost over another, but within the realm of boosts, they're all reaching for a similar kind of thing.
The other side of the coin however is the 4 billion tubescreamer and SD-1 clones out there flooding the market that actually are basically identical to all the other ones.