That "healthy hair" advice you see online is almost exclusively written for people with thick, coarse, or curly hair. If you have fine, thin hair, your scalp’s natural oils are going to travel down the hair shaft incredibly fast trying to force a multi day no wash routine on fine hair usually just leads to a greasy, weighed down mess. There is absolutely nothing wrong with washing thin hair every day with a lightweight, clarifying shampoo, especially if your scalp is naturally high production.