Level cap increase every 1-2 years.

[Tigercub]

Option 1! It kept me and pretty much my entire LS interested in FFXI for 6 years straight, along with most of my friends and acquaintances in the game. There was always so much to do and almost none of it felt pointless.

When you make content redundant or undesirable by comparison, you're losing a big piece of the game. It's a waste of the players' and the developers' time. And if you just keep replacing pieces of the game, the game never grows, it stays the same size. I think it's the reason why some games which will remain unnamed feel like they lack content after only a couple of months of play, despite having been released years ago and having multiple expansions.