It is normal for a 5 year old to be in diapers 24/7.
While a 5 year old is not a baby but a child they are usually potty trained but it's normal for some 5 year olds to be in diapers 24/7.
I have a 5 year old son that is still in diapers 24/7 as he's not potty trained and does not want to be potty trained yet.
I'm sure he will potty train at least by his 6th or 7th birthday and I'm okay with that.
I know another boy that is a Coworkers son that was not potty trained until he was 7 years old and he had no health issues.
I've also known other kids that were potty trained by age 5 and 1/2 to 6 years of age.
My son is home schooled so there's no issue there about him wearing diapers.
My 5 year old wears size 7 Gentle Steps diapers and they are pretty cheap but very absorbent diapers and fit older kids and are mostly plain white.
He will potty train when he's ready and I'm not forcing the issue.
I can afford the diapers and don't mind changing him.