Very true. Even though Sakuraba is known to reuse themes and progressions occasionally, he does a fair job of pushing out a massive soundtrack that gives unique themes to nearly every area or event of the game. Granted, quantity doesn’t always mean quality (especially in the case of Graces), but I admire his work in Symphonia and perhaps even Abyss.
The same applies to Go Shiina, as well. In Legendia, most major areas have unique themes, all of which are excellently composed. One of the reasons a lot of people prefer Legendia’s OST over the dozens of Tales soundtracks is because Shiina’s style is less reliant on just simple melodies and focuses more on instrumental depth and variety. It would have been so easy for Shiina to just copy Sakuraba’s style like he was initially planning to do according to an interview, but Shiina already had his preexisting style and it wouldn’t have been quite as fun for him to pretend to be someone else. I think that’s why Legendia’s soundtrack has a ton of character to it, even moreso than most of Sakuraba’s themes.
Still like Sakuraba more, though.
I’m the opposite case, although I know where you’re coming from because I never finished Phantasia. I knew that it shared the same summons, some of the same locations and even some musical themes with Symphonia, although I never got every reference to Phantasia until after the fact. Still, I wish you good luck on your playthrough of Phantasia!