Look at the panels you posted yourself

Kaidou bonked him so hard, he started to deflate.
Attack was highly effective. Compared to What luffy was landing on kaidou.
You're missing the point.
Not even once Luffy was actively defending against Kaidou attacks.
Gear 4 interaction with Kaidou, is always attacks landing to them. No clash or Defending was done.
Yes luffy can defend, but distraction or not, luffy fate was sealed over there.
If you're assuming Luffy can defend, why not Kaidou with FS lol. When he has already done it with Snakesman. Fastest form of Luffy.
He couldn't have defended.
Show me luffy defending in gear 4.
Their clash would have resulted the same.
On top of that kaidou was already landing his on Luffy while he was doing all the bending with his hands.
Kaidou took on thr same attack, and had his Boro breath blast inside his mouth only. Double damage, yet the very next kaifou speed blitz luffy damaging him to nearly deflate.