Personally I'm not really "up in arms" when it comes to this issue but this article poses some good points. Right now I use both and the telegram app is very convenient and messenger just seems to be the default because most of my friends & relatives are on it.
Maybe once internet accessibility in the Philippines reaches at least 90% (unlike the 37% it is now) and the speed is not as abysmally slow, more Filipinos will find that there are better alternatives to what the masses are used to.
