As it says on the members page:
Moderators have control over everything in the site, except for the Site Manager, which is only accessible by Site Administrators.
Moderators are chosen because they are regular contributors in the community; whether it be on the site, the forums or both. They are chosen because they are respected amongst the community, and are respectful towards others in the community.
An essential role of a moderator is that people can contact a moderator for help. Sometimes people need direct help, and don't know where to go or who to ask. In such cases, they can see the moderator list, because the title tells the community that "this is a person who can probably help me".
If you are not a moderator, this doesn't mean that you aren't respected in the community, that you are not respectful towards others, that you don't regularly contribute or that you aren't willing to help others. The title of "moderator" simply means that the person is all of these things.
Simply because you are not a moderator does not mean you aren't capable of being a moderator. Moderators are chosen for various reasons, and a lot of things are considered. Maturity, how much you contribute, how much you are respected, if more moderators are needed or not. And that is just the start of a list of many factors for consideration.
When I first joined I was a lot like you. Posting a lot, tried to be really helpful, but was also very much a tryhard. It took years before I got moderator, but it was well worth the wait. In the time it took me to earn moderator I matured a lot, and learned better ways to interact online. It takes time, but often it is the only way to learn.