1. The One Piece has been by the sea. You can ask which episode of One Piece didn't mention the sea. If so, you can kill me. Then, you said that most of them were ground operations. I want to say that pirates are human beings. Man is an animal that lives on land. It doesn't make any sense if you want them to stay in the water all the time. For a simple example, everyone has seen the Dragon Ball. This is the most successful animation I have ever seen. Does the dragon ball have to keep saying these seven dragon balls? If so, who else wants to see it? As for the content that combines marine characteristics, there are too many. East China Sea, West Sea, Grand Line, New World, etc. Are divided by sea area. These three naval generals, Wang, Wuhai and Four Emperors, all exist in their own waters. And this story, from beginning to end, revolves around the big secret treasure left by One Piece-One Piece.
2. You said the fighting content was boring, and it was always those times. Which movie isn't? Everyone has his own specific fighting methods and unique skills. You don't have to say that you hope that one day Woosop will use a sword and Thrawn will use a slingshot. That wouldn't be a mess. And everyone's moves are constantly updated (well, you said you watched more than 100 episodes, I don't know exactly how many episodes 100, maybe you didn't watch many), and everyone is getting stronger and stronger. As for the fighting logic you said, which is strong and which is weak, it is divorced from actual combat. Luffy is already very strong, and it is getting stronger and stronger in actual combat. Basically, many characters have fought wars to some extent, and their combat effectiveness can be calculated through the results of previous battles. By the way, the saint is also a very successful cartoon, and the power of the small universe is the most obvious logic.
3. You said that Xiang Jishi was a thug? Who on the spaceship can't take a taxi? Say he has nothing to do, please pay attention. The mode of One Piece is that Luffy constantly meets other pirate groups, and then the two pirate groups break different opponents according to their different levels. Like many comics, most of One Piece is devoted to fighting. You can't say that Ji Xiang can't cook, but even if you were a chef, you couldn't cook at that time. Moreover, Xiang Jishi's kicking methods were all learned when he was learning to cook in a sea restaurant with Zhefu, so the kicking methods all used the names of the ingredients. Straw hat pirates everyone has their own goals. Luffy wants to be one piece, Sauron wants to be the world's first swordsman, Nami wants to be the best sailor searching for all the treasures in the sea, Ji Xiang wants to find all the blue (the legendary sea area has all the legendary fish), and Qiao Ba wants to be the best doctor ... all of them are developing towards their own goals. By the way, every time after the war, as long as he can return to his boat, Ji Xiang will cook a big meal for everyone. You can check it out if you don't believe me. There is no need to describe the cooking skills of Xiang Jishi. From the beginning, no one has said that his cooking is not delicious, which already shows that his cooking is great.
That's all for now. Please feel free to add anything you don't understand. I'm happy to answer.