Not true. Let's go back to 300 years ago, 1720. Back then, illiterate mariners knew that when you perceived an object on the horizon, you could first make out the topgallant masts and sails, but not the deck of a ship. Using a telescope would make the image larger, but you still couldn't see the deck. By climbing up to the crow's nest, you might be able to make out the topmast and sails, but still not the deck. Once again, a telescope would enlarge the image, but was unable to see beyond the horizon. Your statement takes human understanding back to at least to the Bronze Age when Greek and Phoenicians mariners knew this even though that they did not have telescopes. A perfect demostration of idiocracy in action.
Once again, a telescope would enlarge the image, but was unable to see beyond the horizon.
You're still dealing with perspective. Even a telescope, like the eye, has limits.
A stronger telescope (10x vs 5x for example) could have given a more enhanced view of objects further away.
Besides, your explanation doesn't explain how objects which are "over the horizon" and that we can't see with our naked eye because of our limited eyesight, clearly become visible when using a viewing aid.
By your understanding they should never be capable of being brought into view because of the curvature yet they are viewable when using a strong zooming object.