It seems a little odd that if you really want a particular reward for a tier in Final Fantasy XIV’s ranked PvP, your best bet is to get up to that exact rank and then stop. Not totally bonkers, no, but you would think the developers would want you to do as much as you possibly can through the whole experience. This is the reasoning behind the change being made to the reward structure starting in the upcoming patch 6.2, when claiming a reward for a given tier gives you the reward for that tier and all the tiers below it as well.
This will also include title rewards and tiers, although some of those rewards will not change from season to season. It’s a good change clearly meant to encourage players to take part in the battles more consistently rather than giving up partway along the climb. If you’re curious about the other things coming with patch 6.2 when it releases, you can catch back up with the official summary of the first preview from earlier this month.