I'm thinking about buying a new saddle and I have seen that you can still buy high-end saddles without any cut-out / relief channel. I was always advised that I should go for the latter ones since they are healthier on the long run, so I am a bit confused now. Who wouldn't choose that?
The primary consideration in finding a saddle is how well it suits your sit bone shape and groin tissue. Some people do best with saddles that have massive cutouts (heck, even those ones that look U shaped because the nose is split too), while others can use Fiziks or the like that are rounded without any cutout whatsoever.
Cutouts can be disadvantageous as they can increase the pressure placed on your backside (same force but smaller area; imagine how a saddle with a massive cutout resembles a cookie cutter). However, if cutout saddles are what suits your physiology best, you're actually going to harm yourself more by riding an uncomfortable non-cutout saddle.
Saddles are the most personal contact point on the bike.
If you prefer a cutout, or specifically don't like cutouts, then you have the option of either. Gender and differences come into it as well, there may be body shapes that suit one style over another.
While saddle width can be inferred from sit-bone width, noone can really advise what shape of saddle you will find most comfortable.
High-end saddles tend to be low-volume sellers, compared to cheaper saddles, so giving all possible options to the end user helps with choice.
To answer the question as written:
- For many people, the groove or hole does not serve any practical purpose.
- Because the hole takes space, the middle part of the saddle has to be wider so that there is still enough surface area to sit on. This can be a fit problem.
- The hole's edges go pretty much against the part of your anatomy where you don't want any edges.
- The hole introduces an unnecessary weakness in the structure, and reinforcing the saddle adds some weight.
- It gives the impression that the rider is one of the people with genital-related phobias or obsessions.
If the hole or groove makes you more comfortable, it's great for you and nobody's forcing you to buy a saddle without one. But there are some reasons why expensive saddles without these features are sold. It is interesting that it is far more difficult to find a cheap saddle without some kind of anatomic gimmick.