So... Triple Triad

[Genz]

You're not the first to suggest this, and it's a really good suggestion since, not only it makes the 4-stars cards usable, it also adds a much needed depth to TT (it would also be possible to just allow 3+3+3+4+5, so we can use 4-stars, but we wouldn't earn anything gameplay-wise)
Sadly the devs don't care much about older content.

Importing TT nearly "as is" from FF8 was a pretty dumb move in the first place, because it's not that interesting but it was cool 20 years ago since it was "new", and its short-comings could be cancelled by the godly power of reloading a game saved just before playing.
(for example the "combo" from plus/same rules makes the game feel random)
The only accomplishment with FF14 TT is they found a way to make it even worse with dumb rule like Chaos.