Think about which corporation or bank in that country controls mobile payments and why did the government enable it?
Obviously gcash and paymaya were managed by the two largest network providers in the philippines. Everyone uses either of the network and what makes it more convenient is that since everybody is using this two networks you can load up your wallet thro mobile loads.
And yes, this is highly moderated and governed.
BTC was always there but why is no one using it in that public market?
You are a bitcoin user you should know the answer. If I am the vendor i would really not sell it using bitcoin. If ill sell an egg for bitcoin that equates to the value of peso during that tine(eg. 6 pesos) then at the end of the day suddenly the value of that btc ammount drops to 3pesos worth of bitcoin. That is a pure disaster, plus for the current bitcoin situation. If you are the payer you don't want to wait for several hours before you can leave because it took hours before your transaction was confirmed