Most ear infections go away on their own even without medical treatment.
So not much will happen if you do leave an ear infection untreated and not get medical attention for it.
However if you do leave the ear infection untreated the pain may get worse and it will just be painful until the ear infection goes away.
It's best to see a doctor about the ear infection and get treatment for it.
The doctor can prescribe you or your children some antibiotics for the ear infection which helps get rid of the ear infection faster and helps ease the pain.
When my kids had ear infections it was pretty painful for them and after they started taking antibiotics for the ear infection the pain subsided and they felt much better.
If it's a kid that has an ear infection you should take them to the doctor or urgent care or a walk in clinic for treatment.