How is piracy profitable at all in Bilgewater?

From what the Piltover map let us see, the pass to the inner sea between Valoran and Shurima is completly dominated by this city. Wich probably means that for pirate ships coming from Bilgewater is completly impossible to cross this point without huge brives for the harbor masters in Piltover. On the other side, we know Ionia was pretty much an isolationist island continent before the invasion of Noxus, and is still recovering from the war, so there is no real trade coming from their side. And just north of the Blue Flame Islands, all the coast is dominated by the highly militarized Noxus, whose most cities and towns probably hold huge garrisons for protection and keeping order. So because of this, we can also assume they also have a huge military navy protecting their waters and their trade.

So, taking all of these into account, and assuming that what lies in the coast south of Mudtown is either jungle or small coastal towns with no real importance because of their remote location and closer proximity to the menace of the Shadow Isles, the margin of profit and operation for pirates with a base in Bilgewater is a little gap of coastland in northeast Shurima, and a decreasing one in southeast Valoran that is getting dominated by Noxus.

I get there is still profit for pirates that attack trade ships from Piltover to Noxus, but it has to be getting increasingly difficult for them to act in these waters with the ever increasing presence of Noxus military ships, and rising menace of the Black Mist scaring people away from these waters. So why do pirates still consider this place a good base of operations? Wouldn't it be better and much safer for them to stablish a base west of Piltover, that is from where all the trade between Demacia, Shurima, Freljord, Noxus and Piltover comes and passes by?