Well, Dash was used for payment. His privacy allowed his real use.
It dropped harder than other coins, but I still like Dash.
Most of the coins around, including Bitcoin do not have a use case other than speculation. Some coins have some privacy features as main trick but their usage is still tiny. Dash has strong privacy and thanks to instasend, its usable on payments in the stores.
I think dash has the biggest potential to be the coin which used for payments.
But, the world is not a rational world, the best tech does not mean success.