I have researched many websites including Reddit and they said that Baten Kaitos: Eternal Wings and the Lost Ocean 100% is by far the longest speedrun in history??

Congrats to Baffan for getting the WR.

Yep, it's the longest speedrun ever

dude this is the only game where someone has done a WR run in over 340 hours

340+ Hours is like, 2 weeks, right?

The determination is just amazing lol

Yeah, it is

Actually, to my knowledge, since January 2018 the longest accomplished speedrun is Spider:
Rite of the Shrouded Moon 100%: https://www.speedrun.com/srotsm#100

It's not as recognized as Baten Kaitos because there are only 4 hours of gameplay needed. Even Snowfats, the runner, has issue with that: https://www.speedrun.com/srotsm/thread/yuvqx