Honestly we just had an election where I live where the options were (not to this extreme at all) but pretty similar in the "not great" vs "fucking awful" choices. Of course we had an actual third party with good policies but they had no chance. The race was so close here that in some areas the difference in votes was in the hundreds for the top two choices. They're still doing recounts and I guess we'll see, but every single fucking vote has counted on this.
I honestly don't believe that not voting is ever going to work. If we want change we need an actual fucking revolution. Not voting, in American's case, would just allow for the literal militants to take over and then you really won't even have the choice to protest anything in the future.