I wouldn't dream of calling it anything so noble as trying to "raise the collective knowledge". It's a hobby, and I enjoy talking about it. Not sure at what point it became a hobby rather than just wanting to know more about it myself, but it really is that simple from my perspective.
I've actually considered trying to get into manga translation because it's A LOT easier to find work than anime (which I would consider a dream job). Seven Seas is almost always looking for translators, and Yen Press posts job listings a couple times a year. At the same time, I've only ever seen a single listing from CR (for a total of four positions in Tokyo) about a year ago. I was only a couple weeks from beginning my position in Tokyo at the point I saw the listing, so couldn't reasonably apply.
Most manga translation is done by the job, so a translator will work on a single series as it runs. The pay is not what I would call lucrative, and deadlines are constant. There's also the consideration that once a translation is "complete" there's a chance you'll have to revisit the volume if the writer (story and translation are done separately) needs/wants to write a specific way. If the writer puts anything too far from the original there's a chance of conflict in later story lines. The translator (or their supervisor), because of having access to further story line, will usually be the one expected to know this.
With all that amount of work, and being contracted for a specific run, it couldn't be considered a livable wage, and is usually done by people that already have other full time jobs to support themselves. In my case, I'm already working 60 hours a week, and although I would like to do it at least once just for the sake of bragging rights (gotta admit it would be cool to know that I translated a manga), I just don't have the time to dedicate to a project like that.
On top of my already hectic schedule, I'll apparently be taking a full course load of classes beginning next month (haven't been a full-time college student in 18 years although i tend to take 2-3 classes a year for professional development) as well as an 8 hour a week certificate program. I got told last Friday that there's a VERY good chance I'll be going back to Tokyo next year, and have to have these classes for the position.
In the end, regardless of what I think would be cool, my schedule wouldn't allow me to devote the time to any sort of outside translation work.