What led you to that conclusion? I'm curious.
If there's a single one thing you need to do to become a better writer, it's "read," or "write." The supercombo is both. Anything after that may help individuals or even lots of them but is not essential and will work to varying extents based on luck skill and temperament. Advice like this implies "enter enough competitions and you'll slowly get better until you win them," right? Because you compete and you start at 0 but you have to get better because you're competing, right? And then the competing feeds on the competing until you're just the best because why would it stop at any point if competing makes you better? and that's just not what happens for a lot of people. The field is too big. You can't all win #1.