Not so fast. What is called “sea level rising” is also base level of terrain sinking which people perceive as rising seas. It can easily be the case.
The landing beaches of Caesar in England are now a half mile inland. The sea is about a mile from Thermopylae today also.
It is very probable that this road is exactly when they claim. Also it’s easily proven due to Roman road building techniques.
Yes, the Venice area is well known for subsidence. It’s probably a combination of subsidence and a sea level rise (which has been modest the past 2,000 to 3,000 years).