I don't understand what you mean. Is your point that taxes can be justified, and that sufficiently advanced piracy is indistinguishable from taxes?

Yep.

Or that taxes are better than pirates?

Generally they are because taxes tend towards efficient banditry at the Laffer maximum. A pirate spending a fraction of their income on efficient charity probably beats out taxes. Naturally a better utilitarian solution is to give that pirate more and more power so he can better and better approximate taxation and spend more on efficient charity, until the marginal gain of efficient charity drops to that of other government spending. Now of course maybe taxes are already too high and do more harm than good, in which case the pirate should stop earlier.

Or that taxes on trade routes are better than other taxes?

I didn't mean to claim this.