I agree Bazza, if you're not struggling with grip then there is no real need to do grip work.
But saying "I deadlifted 200kg just fine, no grip work so grip work is bullshit" is a laughable comment at best. Nobody gives a fuck about a 200kg deadlift and it doesn't mean shit. 300kg is pushing it honestly. But then again doing extra grip work will never hurt things and I don't know why people are so reluctant to do it, other than laziness or apathy
As an aside I do most of my pulling exercises with straps. Not deadlifting but my shrugs, rows and pulldowns. I find it a million times easier to pull with my elbows instead of my arms if it's not my hands physically gripping the bar