Prepaid cabs at T2 are lifesaver

Whenever i land at T2 i always take the ac prepaid cabs. They are available at half the price of Uber/ ola. I stay in goregaon and from T2 uber shows price of Rs 700-1000 whereas prepaid cabs drop me for Rs 400 I have hardly seen any queues for prepaid cab booking counter inspite of fact that they are cheaper. Not sure why so less people use it