User blog comment:Fliu/Chapter 946: Luffy's Next Big Step/@comment-180.191.122.111-20190622004046/@comment-2600:6C5D:5D00:1C9:C47D:EE3D:4476:E604-20190625160707

You forget. Speed equals strength, like Kizaru's Light Speed Kick sent Supernovas through buildings. Luffy can't match the speed, but he proved to be faster than Lucci and even used the friction to heat up his fist to recreate the Fire Fist, even under water. Third Gear gave Luffy the durability of a Giant, and with his strength, he was able to knock out a sea monster in an instant. Fourth Gear Normal Form costs the length, but worth the power when it condenses and unleashes it like an eruption, and it has multiple forms to handle any adversary at the cost of speed or strength.