If building a port with Infrastructure is the only requisite then Chennai port along with Ennore Port (Both are major ports just 40km apart) and there is Tuticorin 500 km down south or Cochin port on western side should have been successful. You have to convince global shippers to make their transhipment here. And that's going to be awefully long time.
They already have established transhipment routes and changing location to lets say Vizhingam , will require new money on their part, which they wont do until unless they find it profitable. Remember transhipment is just like airways where we transit through major airports like Frankfurt or London, and both are connected to almost all cities on the world. Samewise Colombo is connected to many cities around SE Asia including Indian ports.
Kerala, with communists running around, I find the prospect of the port succeeding. And good luck convincing the global shippers to move from Colombo to any port in India. We can do it. But it will take time. Even China has not been much successful in this. Most of their transhipment happens through Singapore and Klang in Malaysia and they have been trying unsuccessfully for many years now.
Did you even read my post ?
1. DEPTH of the port is the KEY to being a Transshipping hub.
2. Second is COST of the port. (This increases with rate of dredging, related to depth)
3. Third is cabotage relaxation. (allowing foreign ships to do move containers locally)
This is NOT like airlines. Natural ports are RARE.
Besides Colombo and Vizhingam is just 1 hour by ship. Right next to each other.
Adani port will be private , so kerala govt. can't do much there.
Cochin port is a GOVT. port. Is pointless to expect efficiency from it.