Is it better to start on Upwork or try cold emailing directly?

[Btaliat]

There are some freelancers that believe in starting on Upwork first. They don't really believe in sending cold emails. They believe that they can leverage on using Upwork in building and getting clients. There are more than different ways by which freelancers can get clients on Upwork. In a contrary, sol people can send cold emails to the cliekts that they want to work with. Which one will you prefer between working on Upwork or involving in cold email?