Should I apply conditioner or not? {Hair Care}

PS: This post is in perspective that leave-in serums are used after washing the hair. 

A week back, I was too tired of washing my hair and applying the conditioner and waiting in the shower so I made a simple process by simply washing my hair and sticking to the leave-in serum. And, I found my hair was really fluffy and well-behaved and was not weighed down for 3-4 days which wasn't there earlier. This prompted me to think if the conditioner is really needed for hair?

Fine Hair and Conditioning

Since I have done the article on hair textures, I have been inclined to think about hair care separately for both kinds of hair. Yes, conditioners are very necessary for hair but then a lot of other things also affect it - amount of conditioner needed and types of conditioners needed also depend quite a lot on your hair texture, right? So, why to make it a universal rule that you need a conditioner for your hair howsoever your hair and leave-in serum is also a conditioner. 

Conditioner keeps hair soft

But, there is another perspective that conditioner does keep the hair soft. So, leave-in serum's job becomes easy - to protect the loss of moisture. And, conditioner helps detangle the hair too by providing a little slip to the hair. And, many conditioners are able to tame frizzy hair. But, conditioners also have  big disadvantage - they can weigh the hair down. 

So, what do you think - Conditioner or no Conditioner?