There are two types of Finisher move as far as I'm aware, the type that are short and concise in slow motion, and the type that are long winded, elaborate, and brutal.
The long finisher animations snap you into what's basically a cutscene in the middle of combat, rendering you unable to do anything else but also invulnerable, this is the worst of both world as it both breaks the flow of combat something fierce, but also break the immersion of being in the middle of a fire fight where everyone is shooting you but you take no damage.
Additional flaws of this design being if you have any passive effect on a timer, they will be slowly ticking away, and on the other hand of the spectrum, your stamina regenerates during of the animation, and all of your cooldown is still going, which is not great for gameplay balance.
There's no need to remove the long finisher animation either, Skyrim got this figured out long ago, just only play long finishers when you are using it on the last enemy in combat, the one that will end the "in combat" status, this way you don't break the combat flow, and also get to have a satisfying ending to the fight.
The long finisher animations snap you into what's basically a cutscene in the middle of combat, rendering you unable to do anything else but also invulnerable, this is the worst of both world as it both breaks the flow of combat something fierce, but also break the immersion of being in the middle of a fire fight where everyone is shooting you but you take no damage.
Additional flaws of this design being if you have any passive effect on a timer, they will be slowly ticking away, and on the other hand of the spectrum, your stamina regenerates during of the animation, and all of your cooldown is still going, which is not great for gameplay balance.
There's no need to remove the long finisher animation either, Skyrim got this figured out long ago, just only play long finishers when you are using it on the last enemy in combat, the one that will end the "in combat" status, this way you don't break the combat flow, and also get to have a satisfying ending to the fight.