Ok this is just sad and depressing. I can only assume that after FT ended some people needed to find another outlet for their pent up frustrations and decided that OP was the next best thing. What some people have been doing for a while now is being nothing more than an eyesore as you whine for the sake of whining and you use that as an excuse to hide the reality you don't even bother thinking. It's like an automatic impulse: complain immediately.
I mean look at this ^, that doesn't even make any sense. Luffy was able to hit Dogtooth, meaning something was different and Luffy believes he knows what that is. This is one of the most fundamental basics of any kind of fight: find out the weakness of the opponent and exploit it. Your reaction? "That's whack AF". What?
This is the truth: there is nothing particularly unusual about this fight, you just want to whine. Yes this is a manga, so there's always a certain amount of things being 'manipulated', but you shouldn't pull this out of proportion. The way how some people here are dissing this fight is so narrow-minded, restrictive and even borderline draconian that if you would consistently apply this to any existing fight in any fictional series, almost all of them would be complete crap.
The fight is not the problem, it's this twisted and irrational way of viewing the fight that's wrong and there's quite an easy way to underline this. The most important thing we learned from this chapter is that Katakuri has some kind of weakness and Luffy figured out what that is. Now the most logical thing would be to discuss that potential weakness...something barely anyone has done in this thread. Instead it went immediately to "he's being nerfed". That's complete BS. You can only talk about nerfing if you actually know all the factors involved, which none of you do.
Now imagine for example that Dogtooth needs a huge sugar intake from time to time to function at full capacity. Oda often gives characters themes that are complementary with the character's ability. Like Perospero, a candyman who is licking a lollypop all the time. Now Dogtooth is made out of mochi, a substance that's most of the time sweet and thus sugary. So that he would be addicted to sweet stuff wouldn't be that much of a surprise and people who are full of sugar are highly active. However the moment such a sugar rush is over they become kinda sluggish. So what if Dogtooth's punctuality of eating his snacks at always the exact time isn't just to appear disciplined, but also to maximize his energy output?
Due to all the things that have happened his snack-time got delayed quite a bit. This would explain why Luffy was preforming better the longer the fight lasted as Dogtooth was being drained of his sugar and why he abruptly tried to end it by burying Luffy and then immediately started eating.
Is this true? I don't know, it might be complete bogus. I do know however that this is the kind of logic Oda often uses as it makes just enough sense to work and that it's something Luffy surely could figure out because he has got the same relationship with meat. This is how you should approach and discuss a chapter, but instead it's "oh no, he has a weakness, he got nerfed! Booooo". You're not even trying to think about the possibilities and that's just depressing. You just make arbitrary and questionable assumptions and then complain when they are not met.