Too Long; Didn't Read
The main requirements for a convenient chat tool are: correct displaying of the messages on any device. There are ready-made components available for the developers in various JS libraries and frameworks. The pros of exploiting fully-fledged chat/messenger components are numerous: the solution is created and tested for you by a team of experts the technical support and online community are ready to help with any issues. It depends on a particular customer's requirements, with numerous functions and only the most common ones.