I could write an essay on the problems with Final Fantasy 12, but in short it is a trainwreck that is full to the brim with interesting and inventive elements that all fail to work in the most engaging way possible making for a truly enthralling experience that has earned its place as being one of my favourite yet most hated games.
You can take any element of it and break down how it works against the game, for example weather effects where areas can have different weather states that change the enemy variety and accessible areas which should be a good thing but the way the weather changes can be effected by such arbitrary things as needing to approach the area from the west entrance at a 20% chance which cannot be triggered by approaching from other directions and there is a specific hunt locked to that weather in the area making merely finding how to fight the thing needlessly awkward.
Or how rare game enemies can have varied ways to encounter them ranging from things like killing X enemies of a certain type, or just a random chance of appearing, or being at low health in the area etc. yet you then get ones that require a chain of bat kills without breaking it by killing other enemy types, yet there arent enough bats in the area to spawn it, meaning you need to run around killing only the bats fleeing from the other enemy type and then doing a full loop of the area until the bats respawn and then repeating it in order to spawn the rare game with nothing telling you this.
Then there is the treasure, everyone who talks about FF12 treasure talks about the Zodiac Spear being permanently missable from looting treasures earlier in the game, but that is merely the tip of the iceberg when it comes to bullshit treasure chests. There are 2 more ways you get screwed over with treasures, the first is random chance where some of the best items in the game are only obtainable as a random 1/100 chance from looting a specific chest which itself only spawns 1/10 times when entering the area, one of these at least not being "too" annoying to try for in a mine, but the other needing you to take an airship transport and then go to the deck to loot an INVISIBLE chest that has only a small chance of even being present for again a rare chance of the item being inside it, people have since found ways to manipulate RNG to make this reliable but that doesn't mean it didn't exist in its original state to begin with. But the 2nd way treasure screws you over is much, much worse. Unforgivably worse to the point it might be the single most despicable part of the entire game. That is the Diamond Armlet an accessory which in its description lists its ability as making you loot better items from chests. What the Diamond Armlet actually does is it changes the loot table for chests replacing the original item with a different one which, in most cases, is worse than the original. Some of the best items in the game become unobtainable if you loot the chest with the Diamond Armlet equipped, and the few times the Diamond Armlet actually does give you a better item than the original there is still a high chance you don't get the item as it only has a percentage chance to give its replacement item otherwise it gives you a knot of rust instead (which in its own way is valuable but usually worse than the item you are after). In practice this means the only way to really open chests in FF12 is to play with a guide open listing the treasure chests of the area to let you know which are safe to open with or without the Diamond Armlet and needing to sometimes save the game before opening things incase you don't get the item you need.
I could continue going on about all the problems in this game, it is awful... yet I love it, it might be my favourite game in the series after 14, as for all its glaring, terrible problems I can't stop loving that these problems even exist in the first place, it truly lives up to being a "trainwreck", you don't want to look, but you have to, it is too engaging too enthalling to look away from, it is a masterpiece, a wonderfully flawed, terrible masterpiece