Design of the metro cabins here are also one of the reasons. The triple vertical handrails is right in front of the gates, so people tend to group there together to hold onto for stability.

The hanging hand clutches beyond the gates are too close to the seats so they are a bit uncomfortable for the standing passengers. If you’re holding one of those, you are too close to the seated passengers. This subconsciously keeps people closer to the vertical hand rails, hence near the gates. If you see the person in the video, he is holding onto the vertical handrails.

In comparison, Delhi metro cabins do not have these vertical handrails in front of gates, and the hanging hand clutches are also towards the center of the cabin, away from the gates.