In the bigger picture I would say that Fairy Tail is right now worse than Black Clover! Black Clover has a lack of "what comes next", that is true. But the way Fairy Tail treated his "next", is pretty badly. And nope I'm not talking of fights.
In fact Fairy Tail problem is not just fights, if that was the case I would be very happy. Fairy Tail has a ton of problems, and fights is just a minor one at that.
About One Piece beginning quality. There is a good reason why it got a FULL COLOR CHAPTER by its 12th one.
When you limit your perception of a series just by hype and fights, you also limit the worth of the series. But still I don't see how the fights prior to Arlong Park weren't cool and good. At that time we were discovering Luffy devil Fruit ability and his creativity, Zoro excentric Sword style, Ussop strange and kiddly projectile profeciency, Sanji extravagant leg techniques.
Remember the first Gomu Gomu Pistol? In the 1st chapter against the Sea Monster. The first Bullet Ricochet? Against Morgan and the Base Marines to save Zoro and Coby. The First Muchi? Right after Zoro stopped the marines. The First Fuusen? Against Buggy Dama. The first Hammer? Against Richi the lion. The first Bazooka? Sending away Buggy.
All of those attacks and many more, and also from other characters were shown in impactful moments and presented in a really cool manner.
Though One Piece shined in the Thematic, Motivational, Adventure, Comedy and Drama aspects. When you have an arc with a Clown Pirate, with the major thematic being the value of things, of treasure, you have Hachiko, you have a unexpected deep connection between characters, and all of that is greatly oven into one single thing, than I don't know about you, but for me that is a 5 star arc.
Note also the fact that the series had really great story and its direction, great paneling and flow, with great and impactful characters designs(while being wacky), and great world design. that in the beginning was the weakest aspect of One Piece, and it improved so greatly that right now is in such an incomparable level) were big aspects for the series success.
Things didn't only started happening in Arlong because, but not only Luffy, Chuchu, Sanji and Zoro backstories, Krieg and Mihawk and Kuro and Buggy.