Not only does it make you hit it bad, it reduces your club head speed.
This is not to say you can cure all of your problems by gripping the club like an injured bird; that can cause you to increase grip pressure during the swing. That is worse than tight grip pressure to begin with.
Tight or increasing grip pressure slows the turn of your shoulders, as any excess tension will do. The shoulders being free to turn will increase club head speed and accuracy.
Find a nice comfortable grip pressure and keep it constant by using your lower body and shoulders to swing the club, not your hands and arms.
You’ve heard the cliche…swing with the big muscles.
This one is very important. I am going to re-post on Monday when there are more readers.