Wikipedia is, by definition, the encyclopedia anyone can edit. However, everyone contributes in a different way. Some people create stub pages. Some take those stub pages and turn them into pages with significant detail. Others perform copy edits on pages to pull them to a fully refined and easily readable quality. Still others spend their time protecting those developed pages from persistent vandals. It takes teamwork from all of these differing editors to be able to create magnificent articles. This doesn't even consider the ever-important roles held by administrators, bureaucrats, bot operators, tool developers, and countless other roles that keep Wikipedia coherent, organized and efficient. Without work from everyone, Wikipedia would not be what it is today.
All of those positions are necessary. Missing just one of any of those groups would severely cripple Wikipedia's usefulness. But no matter how hard anyone tries, there is no way all of those roles can be filled by a single person. Wikipedia is a team effort and it takes contributions from everyone to get us where we want to be. Because everyone is different, editors fill in different roles based on what they enjoy. There is no "right" or "wrong" way to contribute to Wikipedia. While I may not do certain tasks, I recognize that those tasks are vital to Wikipedia's success and am thankful for all of the editors that have filled in where I have not helped out.
Personally, I enjoy and focus on the following tasks:
- Vandalism detection, reversion, and vandal reformation
- New page patrolling
- Discussion at WP:AFD
- Copy editing and review
- Policy development