Jedi do have incredibly heightened senses and reflexes, yes, but in my mind there’s another reason they’re so preternaturally skilled at “blocking” laser bolts: lightsaber blades attract them like magnets.
Something to do with the forcefield that keeps the blade intact, or the way the energy is generated from the kyber crystal, makes nearby laser bolts ‘bend’ toward it, deflecting them harmlessly. It does this so quickly, though, that it’s almost imperceptible to the naked eye. So despite appearances, the laser-deflection is thanks not only to Jedi reflexes, but also ancient technology.
This is an open secret among the Jedi themselves, but something they generally don’t mention to outsiders in order to inflate the mythic quality of the all-powerful Jedi.