This makes me wonder why Minato never marked his students with FTG, just as a precaution, to save them in a second when they needed help?
Minato lost his students in one year as a team, that's a lot of incompetence for such an intelligent character, and FTG is broken.
Like, Minato is able to teleport to any place marked with FTG, and FTG can't be removed under normal circumstances (Obito becoming the Ten-Tails' Jinchūriki was the only way to remove FTG).
Naruto has many plot holeswith Minato and FTG.
If Minato had marked his team with FTG:
• Obito, he could have saved Obito from being crushed by a rock. He could have saved Obito from Madara. He could have eliminated the elderly Madara.
• He could have saved Rin, fixed Rin's seal as Isobu's Jinchūriki, getting another Jinchūriki for Konoha.
• It could have prevented Kakashi from losing an eye, and Kakashi wouldn't have needed to kill Rin to save Konoha from an Isobu outbreak.