Ok everything Ryke12 said i agree with.
First off if you mean FF games getting worse since FFX then you cant really complain since there really hasn't been a true sequel yet. FFX-2 i've never even played since it looks like FF charlies angels style or some crap, and FF11 is an MMORPG so you cant compare it to other FF games.
As for Tactics advance and FFCC i love those games, spent way to much time on FFtactics and FFCC is a great real time rpg, as fun as Secret of Mana or Secret of Evermore (if you dont know those games then your not a true Squaresoft fan)
I think that the FF series is just evolveing with the new technology these days and i personally think that its a difficult thing to do to change the ways and implement full 3D and voice acting and all that stuff, FFX didn't really suceed in that sense, the level design was too plain and there was way too much dialouge seens.
From what i've heard FF12 is going too rock though and the story so far is pretty darn good so look forward to it.