Why do you think I don't like his character?
Not his character, but you seem to underrate his abilities.
"Every Kage/Sannin/High Jounin can defeat him". I won't take you literally on that since High Jounin's aren't enough to defeat him, but the fact remains about you underrating him in a way.
He can take Mei, the 3rd Kazekage, Gai, Kakashi, 2nd Mizukage Sasori, Deidara, Konan, the 4th Kazekage, Gaara, Yagura and most Jinchuurikis, and a few others i can't remember.
If you actually analyze his abilities you'll notice that. He hasn't shown his full power in a 1 vs 1 because he's never been granted one. Battles including him are designed to stack the odds against him.
e.g. Naruto, Kakashi, Ino, Chouji and Yamato vs Kakuzu
Chouji, Darui, Tenten (with a treasured tool), Ino and a few others fought him in the war.
In a 1 vs 1, his hearts are almost impossible to take down. How can they be taken out whilst he's supporting them at the very same time ? His Doton Domu makes him immune to physical attacks e.g. All Taijutsu and Kenjutsu users
This adds:
The 7 Ninja Swordsmen
Hanzo (Possibly)
Mifune
Darui
Tsunade
and any close combat fighter to the list of people he can beat.