There are a bajillion crappy old games that I actually dislike more, but none of those would be interesting answers.
Of games that are generally well-regarded, so the gap between my opinion and the common opinion is largest, I’d have to say Final Fantasy Tactics.
It’s not that I dislike it - it’s just that, between FFT and Tactics Ogre, there are five games of the same type from the same devs and the same general era (FFT, FFT Advance, FFT A2, Tactics Ogre: Let Us Cling Together and Tactics Ogre: Knight of Lodis) and IMO, FFT is the bottom of the barrel - every single one of the others is better.
FFT is a game I have played through 3+ times with probably 1,000+ total playtime and I’ve played all the games you mention. I recommended FFT to a friend a few years ago and watched him play through the first couple missions and it’s easy to forget the difficulty curve of that game if you haven’t played an older style TRPG. A lot of the mechanics aren’t really explained well (stat growth for example), there’s permadeath, a few instances of possible softlocking, and a bunch of really obscure requirements to access some of the content and recruit some of the characters.
I think it suffers from sequel syndrome where the newer TRPGs have better quality of life aspects to them. That said there are rumors of a remake that maybe will address some of that.