What is the surfactant's role in the non-coalescence of water droplets?

I have recently seen many videos that talk about the noncoalescence of water droplets; however, I do not understand the purpose of adding surfactants into the water. From my knowledge (high school), objects will stay on top of the water due to water's cohesion, resulting in a high surface tension. This is why in an experiment of a paperclip floating on water, when you add soap, the paperclip sinks - due to the decrease in surface tension. What I am really confused is that the noncoalescence of water droplets works BETTER when surfactants are added. It would be great if anyone has an answer, I am really puzzled...[![enter image description here](https://i.stack.imgur.com/a0Upy.jpg)](https://i.stack.imgur.com/a0Upy.jpg)


