I think engaging ~= fun ~= graphics
we are all visual animals, so visually pleasure is hard to avoid and deniable.

I think something, especially so much games out there, can make you engage to it. it means some certain degree of successful. unless...you knock ff14 up by accident...
oh that's off-topic...

The rest is personal opinion and preference. Judging other ppl's fun according to personal preference is not appropriated.
If you decided to be engaged with this game out of million games & fun stuffs out there, it means this game is more fun than others... even though lots time it's a game of eliminate the worst not choose who's better, like the election...
and you know...no baby, no problem. door is over there people can walk out there.

For me personally I think ff14 is super fun, in terms of battle style, graphics, music and story line, I see other games as inferiors. that's why I engaged to it. Even though I cheated to GW2 D3 sometimes, but I always muttering "inferiors" when I see the graphics, music, story lines...