When you pass up edges it actually makes it harder to use any skill advantage that one may have.  First it is a skill to know when and where your edges are and second good players don’t pass up edges.  They embrace them.  

Sure if your cEV in a tournament situation is something like 0.03 BBs, then this is one of those close situations that one can pass up.  But in general, if a play is over 1 BBs profit in early stages and over 0.3 BBs in later stages, you are supposed to take those edges.  

Also as shown in Matthew Hunt’s article that Andrew posted above, that as stacks shrink so does your edge.  In general this is because most of the bad players make their biggest mistakes when they have the most chips.  If a bad player has 200 BBs, his capability of error is as much as his stack.  Additionally, each error is not 100% of the chips he puts in.  Imagine if a bad player invests 100 BBs on a bet when he only has 85 BBs equity, his error is 15 BBs in that spot.  

When the stacks shrink to 20 BBs and a bad player invests his 20 BBs in a spot where he has 15 BBs equity, his error is only 5 BBs.  That partly explains why it is harder to “create” an edge in later spots.  The error margins are smaller as stack shrink.  

Your edges do not come from your superior play, but in capitalizing on your opponents errors.  Poker is a zero sum game, therefore, you cannot create profit.  If two perfect players play each other, theoretically with enough hands, they should each break even.  Your profit is not created by you, it is the result of your opponents making errors and you being able to capitalize on the error.