Feelings on FF14's Trinity System?

[LilimoLimomo]

If you’re the main tank all your attacks are going to hit at the front anyway.

This is probably true most of the time, but there are plenty of exceptions. It's pretty common for bosses to have attacks where their facing isn't determined by their primary aggro target; Coin-counter, the ShB's dungeon Berserker, the normal raid Shadowkeeper fight, etc.