Let me twist your mind and I want you to research it

Dwarka is carbon dated as 10000 years old. Means it was build 10000 years back

The available data says that in last 10000 years, sea level had increased by 150 meters

The current depth of sea around and between India and Sri Lanka is 90 to 100 meters

Now Ramayan is much older then Shri krishan era means much older then Dwarka

This means there was no water between Sri Lanka and India

So the question i am struggling with is, Why Shri Ram need Ram Setu?

Or the real Lanka is somewhere else?