Ask HN: Can a startup idea succeed solely based on execution?

Let's say I have an idea which someone has already built.

But I execute it much better in some way. (Eg: cost efficiency / user experience / whatever). So there might be something else which is approximately same as my application, can I win based on refinement or efficiency of execution?

Or is it more likely the competitor will figure out the way to realize the same efficiency gains?

What are some examples of this succeeding and failing?

Any personal anecdotes will be appreciated too.