I guess you're still new to online gaming? If so, then welcome! FFXIV is indeed a subscription-based MMORPG like World of Warcraft where you have to not only pay for the game itself (which pays for the game's original development), you also have to pay a regular subscription fee, which pays for the cost of maintaining the expensive servers that the game runs on, as well as paying for new content that is constantly being added every few months (we've got a new content patch coming in a few weeks in fact), along with patches that fix bugs and problems, things like technical support, and more.

And given the fact that MMOs rarely have no true 'end', your subscription is basically paying to extend the game pretty much indefinitely beyond the 'initial' story.

But we all have different priorities and expenses to cover in life so we all have to make the choice whether paying to play this game is for us or not.