Palpatine can rip Senate Pods out of their durasteel restraints, lift 3 of them up in the air and throw them..with ease. .Each one is about the size of a car. We saw how fast Yoda is but where is it even suggested anyone in Hp is that agile? If Palpatine starts chucking things at Voldemort, he can of course apperate but precog kinda renders "poof and I'm here" useless.
Also, Force lightning and Force choke are far more impressive than turning "fiery rope" into a snake.
Also, even non-spoken spells can be dodged. There's also the nasty business of Palpatine just yanking Voldemort's wand away and breaking it in half. Voldemort has nothing to counter it...unless you can provide an instance he resisted this?