I hope the PvP rework in Endwalker will change this.
It's really a waste of ressource to make theses just for a few hundred.
A portion of the more competitive community might be against it and probably want more unique limited rewards, but imo rewards should only be limited for a time, like keeping the current system for the current season (or last X seasons) and opening older rewards to be obtenable by alternative way.

It's alse kind of strange to have this alien reward system when the whole rest of the game don't do it, on the contrary, it's usually easier to get them as time pass.

They even rework the sub rewards to make it easier for new players to get them and not having to wait years.
So it wouldn't feel strange if they also end-up changing the PvP rewards to align it to the rest of the game.