The first disc definitely feels more linear and story driven than later discs once the game opens up and the story kind of comes to a standstill for a while because you start roaming around for the various minigames, treasure hunts, and backtracking all over the map. The Chocobo Hot & Cold minigame was annoying at first but it kind of grew on me a bit by the end. Hunting for the Chocographs was rather annoying at times, especially when none were popping up for nearly an hour... But once I found them all it was a cinch to hunt the world map for the treasure and the rewards for doing so greet you with a lot of the best gear in the game. Then you gotta hunt over the world map once again to find all the beaches for the Fat Chocobo sidequest. And then the whole Kupo Nut thing where you can only hold one at a time so you gotta ensure you don't deliver any mail to a moogle until you've ran back to deliver the Kupo Nut you're currently holding, only to once again run back there to deliver the new Kupo Nut as well.
The ending to the game does seem somewhat rushed in the end and then the final boss literally comes out of no where... There was never any mention of him or anything that I'm aware of. He just shows up and is the final boss. Then the credits roll and you get a short extra scene that is suppose to close things off but ends up leaving you wanting more and having a lot of questions that obviously never get answered making the ending as a whole feel underwhelming. And unfortunately there's no New Game+ system to replay the game starting off with all the gear you've grinded for... and a lot of the late game gear underperforms to the stuff you already found from the minigames... Or you're hitting the damage cap anyways with weaker gear so it's like what does the higher numbers even do at this point ya know?
It doesn't help when the highest HP boss in the game only has like 55,000 HP, yet every character hits for 9,999 by that point. Hard mode whats that? Am I right? lmao. The game is a breeze if you do everything. Even the superboss Ozma, only managed to one shot two characters before I took him out without ever requiring healing or playing defensively. Simply running with the Attack button on physical characters and going with Flare on Vivi and Bahamut on Dagger is a strategy that works on everything by the time you get them until the end of the game.
Amarant is still easily the worst of the party members and his growth as a character happens painfully slow and by the end you're questioning if he's actually changed at all or if it was surface level.
The card game in FF9 was absolutely pointless. Other than the tournament in Treno you can go the entire game without playing it. The rewards for playing it are solely cards your opponent used that you beat in the game and you never are required to play it again past the tournament. So the only reason to play it more than that is if you either want to collect every card or if you're going for the 100 wins achievement. In the end I got the achievement but I didn't get every card. There is 100 different card types in the game, and by default you can only have 100 cards, so you're only able to keep 1 of each card if you want to collect them all. I think I got somewhere around 68 of the cards but I couldn't be bothered to try to collect them all as it'd entail finding select people to battle that hold whatever card I needed and then playing them over and over until I won a game while having taken over said card in the duel... and I just didn't care. The actual battles in the card game have a degree of randomness involved in the math determining which card comes out on top and it's just very annoying.
FF8's card game was infinitely superior.
In the end, I loved my time with the game all the way to the end... and I still rank FF9 as my second favorite of the series. FF4 being my absolute favorite for the story and characters, I've played both the 2D and the 3D versions of that one... Some day I'll Play FF4 Interlude and FF4 The After Years. Despite FF4 being my favorite I've never played those.