The core problem is the business model; As in it's entirely intentional.

In content-driven games, content takes longer to develop than it takes to get consumed. It takes a grand total of around 65 hours to completely consume Heavensward (Not counting wipe times. Could take you forever then )

All games get boring after a while, but you stave it off with sand-boxy content and/or activities. The mini-games are an example, but the ones we got so far aren't really engaging mini-games. Hell, Chocobo Racing is a stat-game and an exercise in pressing the W key in most cases.