A lot of FFVIII has influenced other games. You had FFIX use the same engine. And the style of "3 guys, 3 girls" as well the girls being "jail-bait, dark side, girl next door" archetypes carried over into FFX and XIII. I think it really defined the kind of story you get in those games as well. Of course there's the gunblade. I don't know if FFX really would've gone for a love story if FFVIII didn't do it first. And of course, it was a huge revolution in sound in that Uematsu finally left the chip behind and moved straight into samples. I think that made a tremendous shift in the RPG genre, and I can't honestly say if we're better off for it. When you combine that with the story feel, you essentially have how Kitase & Toriyama view RPGs. And then of course we have how it changed summons.

I don't think FFVIII was a radical departure with its game mechanics, as far as getting rid of MP and armor (I would argue FFII's is more out there from the series). But I do think it was the most complicated. Essentially, it continued the tradition of FFVI and VII, of breaking down FFV's classes into its constituent parts. FFVII already really changed the armor system, FFVIII just went one extra step. Still, I think it was a very complicated route where magic determined EVERYTHING about that character, even esoteric stats like status/elemental damage, there were a lot of different ways to obtain magic, and a lot of crazy things to do with enemies, not to mention how the separate card system plays into the customization as well. There were so many insane options, unfortunately when you create a system this large it's hard to maintain the balance and players find the cracks. With a series like Final Fantasy where the players play it multiple times over and research it to find every little advantage, it was only a matter of time before the system crumbled beneath its own weight.

Square has tried a lot of other systems and I think that's what they should do, but I think they know they don't want to go as complicated as VIII. Actually, the unique system trend would be accurate if it weren't for XIII, which I was very off put by the fact that they simply revisited the Sphere Grid with the Crystarium except they made it far simpler. That should have been considered a huge stain on the XIII team's reputation for doing that.