that's not the idea.
for every airliner, they need what's called an en-route alternate aerodrome, that is an airport to land if something goes wrong while flying half way.
before mattala, all A380s from Australia to europe and middle east had to fly on a long route over land (via indonesia region) because there was no airport on the way to land if they flew on a much direct track.
now with mattala they can fly over ocean on a much closer track because if an engine failure occurs over the ocean they can land at mattaa. It's a legal requirement.
(All airliners can fly and land with one engine out)
when they use our airspace they have to pay, roughly around $400.
that's how we make money with mattala