Shampoo is one of the modern day items that people have simply accepted as a necessity in their daily lives. Like most products, it was initially marketed to address an issue that didn't really need a complicated answer to. It was marketed as a solution to gunk forming in the hair, which is something that regular and thorough washing can achieve just as effectively. Aggressive marketing works somehow, as it preys on the insecurities of people. Human nature is such a fickle matter that even in the face of logic, they'd rather succumb to their 'what ifs' and 'better safe than sorry' reasoning. The spread of shampoo is similar to how antiperspirants were pushed into the market. Somehow, sweaty underarm areas became something to worry about, although it didn't really matter prior to their marketing. With constant use of antiperspirants, what used to be totally natural sweaty smell began to smell repugnant whenever people miss out on putting on these antiperspirants. Thus, a deodorant is then added as a feature.
The scalp produces oil to keep hair shiny and soft. However, poor personal hygiene produces clumps of gunk because of the accumulation of dirt. This is a normal function of the oil as well, to collect dust so that it becomes easier to wash with water. As a result, big companies found a market and exploited it as much as they could. On top of that, they have found another market because of the negative effects of shampoo. Conditioners were then pushed as a product that would make hair silky smooth and beautiful. Ironically, that was how shampoo was initially marketed as well. The dynamics between these two products should be red flags already. Consumers are advised to read up studies on this and check it out to see for themselves.
Unfortunately, when everyone has started using shampoo the scalp's ability to produce natural oils have been compromised. Just like how the testicles slightly shrink because of overdose on anabolic steroids. Parts of the body responsible for producing oils and hormones begin to think they shouldn't do as much work so they slow down. So just like quitting drugs, immediately stopping use of shampoo will have negative effects. This is why there are now some companies that manufacture all-natural sulfate free conditioner and shampoos. Unlike shampoo and conditioner with sulfate, these innovative products don't compromise the scalp's ability to produce oil. The problem is that people are still not willing to transition to products without sulfates because it doesn't bubble like how others do. These bubbles are virtually useless and are simply added by manufacturers to make people feel that it's doing wonders during application. There are a lot of helpful information on different websites to help people gradually transition to products without sulfate. These include soaps, dish washing liquids and laundry detergent.
It will in fact feel unusual at first use of sulfate-free products. The absence of bubbles might feel unsettling, but as long as the person knows those bubbles are for playing with their minds, transitioning to sulfate-free products is going to be quite bearable.