I am no expert, but I think that was mostly solved long ago, at least with most educated riders. As I understand it:
1. Get a good saddle. Not necessarily an expensive one, but one that fits you well and has a grove that reduces pressure on the perineum.
2. Make sure your bike is fitted properly, which will help keep you in a position that puts less pressure on that area.
3. Change positions often when riding and when possible work on keeping weight aft on the pelvis.
4. On long rides, get up out of the saddle often to give your backside a break, and even take short breaks if that area is getting at all numb.
5. If you are experiencing any problems or numbness, revisit all of the previous steps.
I only got back into the cycling game again last year at 40, but I know lots of life long riders and don't know anyone who has ever had an issue. I know it can happen, but from what I have read there are usually some kind of odd or more extreme circumstances that lead to the problem. Even then it is usually temporary at first with all kinds of warning signs to make changes early on, so it's not like you suddenly go limp with no warning or opportunity to correct the issue.
Hopefully one of the more experienced riders here will chime in on the subject.
