Don't listen to those people. Vim was very much worth the initial learning curve, for me at least. I never really used Sublime that much, so I can't speak for it. Maybe it gives you 80% of vim's productivity for 1/4th of the effort, but make no mistake, vim is an absurdly powerful tool which I'm 99% sure beats Sublime out of the water (though, again, I never got deep into Sublime, so take this with a grain of salt).

Oh and the learning curve thing is greatly exaggerated, often by vim users themselves, seeking to brag to everyone about how they mastered the "fearsome learning curve of vim".