Really depends on what you're scared of and how reasonable it is to be scared of that thing.

Get back together with your abusive ex? -> Do it! -> But I'm scared! -> Do it scared!

The context matters. This kind of platitude only works if we assume that there are no "real" risks in the world, and that we only have invalid reptile brain feelings. But neither of those things are true. There are real dangers in the world, and many feelings warning us to stop are legitimate.