The point of bracketing in the context you described is to come up with a higher dynamic range that the one you can get with a single picture because you want or need to do it.

Even if RAW has more bits per channel than JPEG, it still have a limited dynamic range. So depending of the scene you have in front of you, you will want or need to take pictures with different exposures. Moreover, it isn't all about RAW vs JPEG, each camera model has its own capabilities to capture a given dynamic range. Basically, if your histogram shows "burned" high light or completely black shadows, information will be missing with a single shot.

If you think that the 0EV shot has a reasonable exposure, maybe you don't need HDR in the first place (you can even get HDR like result from a single RAW).

Now obviously, the EV difference between two shots will be function of the dynamic range you want to capture, thus function of the scene. And yes, in this case some information will be redundant anyway, as what is in the middle range of picture A (say 0 EV) will also be present in B (say -1EV) and C (+1EV). To limit this, you have to set the bracketing parameter to adequate values.

Regarding the number of pictures you need and the EV difference between each shot, plenty of persons have plenty of advices. What works for me as a "standard" (say 1 2/3 or 2 EV difference with 7 pictures for a given scene) may be inadequate for someone else.

I would like to add that the shutter speed isn't the only variable. Some camera can change ISO or aperture to obtain bracketing (use aperture bracketing only if you know what it does).

Kartick Vaddadi provided an example to illustrated how information is indeed redundant, have a look : https://photo.stackexchange.com/a/67276/26456