If you choose to be reborn, you will not have magic powers, but you will unlock a status window and a skill tree that you can use to give yourself new skills and abilities and improve your physical characteristics.
You’ll get the same thing if you choose to be reincarnated, however, magic will be a factor. And the age of the world will be somewhere like 50-ish years before the full rollout of the industrial revolution, technology-wise. (minor clarification, you keep your current knowledge either way)
However, you will not be the hero or the chosen one. You’re just going to be a person with a perk.
Why would I live in a preindustrial society just for the minute chance I could use magic. Because statistically speaking you will be a subsistence farmer in a world where the powerfull can literally alter reality.