In Gita its said that u should become selflessness and statement is given below 

**“Through selfless service, you will always be fruitful and find the fulfillment of your desires”**

― Bhagavad Gita

I thinks selflessness concept in Gita is not applicable in  Kaliyuga..

Because if we become selfless we will become poor and poor

Suppose u  have a-lot of money  and  u donate to all needy people , then u will have nothing

suppose u help other  then ur time will be wasted and u will ruin own life   because time is money

In carrer also , suppose if u r preparing for civil service exam ( UPSC exam) , u have to very selfish and selfish  then only  u become topper .

Suppose  u are  selflessness person  and u are  helping  other by giving  some knowledge to needy aspirant of UPSC candidate , then u r wasting ur own time  and u will not qualify even civil service exam

So we have to think only about self.Then only we become successful person.If we think about other then we  will not become successful.