Improving your vision means being able to differentiate details better. Magnification means that you can make something look bigger.
Having a prescription glasses that adds detail but not magnification means that the small target will still look just as small to you as it would to a person with perfectly healthy vision. How do you think this gives them an advantage over someone with normal vision?
Nobody said anything about 20/20 vision.
Improving your vision means being able to differentiate details better. Magnification means that you can make something look bigger.
Having a prescription glasses that adds detail but not magnification means that the small target will still look just as small to you as it would to a person with perfectly healthy vision. How do you think this gives them an advantage over someone with normal vision?