Everybody has an equal opportunity to earn it. It's possible by writing good content and getting rewards.
These rewards are however decided by a few wealthy token holders (whales). Which in theory have the ability to reward in a way such that they never get out-competed. The way to do this would be to preferably vote for poorer minnows instead of established writers such as @stellabelle - then these established writers could never out-compete a whale. Note: Active whales also get multiple curation rewards which may are about equal or greater size than content rewards would ever generate consistently - e.g. @smooth 7,206 SP past 7 days - few or no other writer made this much this week.