Madara cannot respond appropriately to this attack—that’s the topic. He creates a barrier for one and is too slow for the repeated attacks and a page later he is surrounding himself fully in a barrier.
Gai was pinning down Madara before he had a chance to react
Again, in a combo, which is affected by a sequence of things, instead of just straight movement speed. The first punch serves as a “distraction”, which influence the movement speed vs reaction comparison.
Madara has reacted to attacks faster than the pinned down panel, that you can’t deny.
FTG user’s attack takes time, but usually it’s a melee attack, though fast, but how fast is debatable, which is why I say anybody who reacts FTG, is prob at least comparable to Minato reacting to Lee’s Kunai, which is faster than Gai’s movement.