"He lit up the palace at the speed of a flash of light". Ok, thanks, but where did he move or attack at the speed of light?
It shows that most people in OP are below Mach 1 in movement.
Only in travel speed if we accept the statement from Gazelleman:
We also saw that he kidnapped Tama. I don´t saw any durability feats from her to survive a speed at MHS+-Relativistic or higher. If we already using here logic, we shouldn´t ignore that not everyone can keep up with the friction which happend is someone is forced to move that fast.
I mean, Luffy and Zoro holding back, they don´t take the whole situation seriously.
I can use the same logic and say Meruem
can´t even escape an explosion, what Luffy already did in Punk Hazard.
Either Meruem his reaction speed is bad, or his travel speed. Or both? Joke aside, i don´t think Meruem is slow. I only don´t see him beating Luffy in this term lmao.