Come for the code, stay for the community.
Drupal thrives on community contributions in the form of patches and documentation to both contributed modules and core. This helps the project move forward and stay relevant.
Not everyone who works on open source projects is a senior developer. Drupal is built through lots of little tasks. Smaller tasks help people increase confidence and gain experience, which, in turn, leads to more contributions. We'll build on each other's strengths to learn how to navigate the issue queue while having fun trying new things.