I think it's also important to recognize that seizures are not the only major withdrawal symptom.
I never had a seizure. I never had the shakes. But I had major organ failure and aspiration.
If you are a heavy drinker like I was and are trying to quit without medical supervision, just because you don't have a seizure doesn't mean you're in the clear.
Detox, like the effects of alcohol in general, can vary from person to person. That's why it's so important to get medical help.